Hollow blade with exhaust grooves and centrifugal fan impeller

Abstract

The utility model provides a hollow blade with exhaust grooves and a centrifugal fan impeller, the hollow blade with the exhaust grooves comprises a thin-plate-shaped pressure surface, a thin-plate-shaped suction surface and at least one partition plate, and the pressure surface and the suction surface define a hollow blade main body structure; the inner space of the blade body structure is divided into a plurality of independent subspaces with the two ends communicated through by the partition plates, the end of each partition plate is provided with a first exhaust groove communicated with the two sides of the partition plate, and the end of the blade body structure is provided with a second exhaust groove communicated with the interior and the exterior of the blade body structure. And the end part of the blade main body where the second exhaust grooves are located and the end part of the partition plate where the first exhaust grooves are located face the same direction. According to the hollow blade with the exhaust grooves, the phenomenon that when an existing hollow blade is welded to a centrifugal impeller fan, a weld joint bursts can be effectively avoided, and the connecting strength of the hollow blade, the wheel shaft disc and the wheel cover is remarkably improved.

Description

Technical Field

[0001] The present application belongs to the technical field of centrifugal fans, and specifically provides a hollow blade with an exhaust groove, and a centrifugal fan impeller having the hollow blade with the exhaust groove. Background Art

[0002] Hollow blades have been increasingly used in the field of high-speed centrifugal fans. Since they greatly reduce the weight and inertial load of the centrifugal fan impeller, they can significantly improve the starting speed and response speed of the fan, thereby improving the dynamic performance and energy efficiency of the entire system.

[0003] Since the wall thickness of the hollow blade is much smaller than its overall size, in order to prevent it from deforming during high-speed rotation of the centrifugal fan, it is generally necessary to set one or more partitions inside the hollow blade, and use the partitions to connect the pressure surface and the suction surface to strengthen the structural strength of the hollow blade.

[0004] However, due to the presence of the partition, the interior of the hollow blade is divided into independent sub-spaces. In the process of welding the hollow blade to the wheel axle disk and the wheel cover, at the final sealing position of each sub-space, due to the high temperature of the welding arc, the air in the sub-space expands due to the heat and bursts outward, resulting in a poor seal here, thereby affecting the connection strength between the blade and the wheel axle disk or wheel cover. Utility Model Content

[0005] In order to solve the problems existing in the above-mentioned prior art, the present application provides a hollow blade with an exhaust groove, including a thin plate-shaped pressure surface and a suction surface, and at least one partition, wherein the pressure surface and the suction surface form a hollow blade main body structure, and the partition divides the internal space of the blade main body structure into a plurality of sub-spaces which are independent of each other and connected at both ends, and a first exhaust groove connecting the two sides of the partition is arranged at the end of each partition, and a second exhaust groove connecting the inside and outside of the blade main body structure is arranged at the end of the blade main body structure, and the end of the blade main body where the second exhaust groove is located and the end of the partition where the first exhaust groove is located face the same direction.

[0006] Preferably, the second exhaust groove is arranged on the suction surface, and the distance between the second exhaust groove and the trailing edge of the blade main body structure is smaller than the distance between the second exhaust groove and the leading edge of the blade main body structure.

[0007] Preferably, the second exhaust groove obliquely penetrates the suction surface, and the distance between the opening of the second exhaust groove on the outer side of the suction surface and the trailing edge is smaller than the distance between the opening of the second exhaust groove on the inner side of the suction surface and the trailing edge.

[0008] Preferably, the groove width and groove depth of the first exhaust groove and the second exhaust groove are much smaller than the height of the blade main body structure.

[0009] Preferably, the groove width of the second exhaust groove is smaller than the groove width of the first exhaust groove, the groove depth of the second exhaust groove is smaller than the groove depth of the first exhaust groove, and the groove width and groove depth of the second exhaust groove are both smaller than the thickness of the blade main structure.

[0010] The present application also provides a centrifugal fan impeller, including a wheel axle disk and a wheel cover, wherein the wheel axle disk and the wheel cover are coaxially spaced apart, and further comprising: a plurality of the aforementioned hollow blades with exhaust grooves, and a sealing portion corresponding to the second exhaust groove of each of the hollow blades with exhaust grooves; the plurality of the hollow blades with exhaust grooves are distributed circumferentially spaced apart between the wheel axle disk and the wheel cover, and the two ends of each of the hollow blades with exhaust grooves are respectively fixedly connected to the wheel axle disk and the wheel cover; each of the sealing portions is airtightly arranged at the second exhaust groove of its corresponding hollow blade with exhaust groove.

[0011] Preferably, the second exhaust groove of each hollow blade with an exhaust groove faces one side of the wheel cover.

[0012] Preferably, the hollow blade with the exhaust groove is fixedly connected to the wheel axle disk and the wheel cover by a welding process, and the sealing portion is fixedly connected airtightly between the second exhaust groove and the wheel cover by a blocking welding process.

[0013] The hollow blade with exhaust grooves provided in the present application can effectively realize air circulation between various subspaces and between the inside of the hollow blade structure and the outside world during the welding process by setting a first exhaust groove on the partition and a second exhaust groove on the blade main body structure, thereby effectively avoiding the problem of weld bursting in the final stage of welding due to the heat expansion of air in each subspace inside the blade during the welding process caused by the setting of the partition. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a hollow blade with exhaust slots provided according to an embodiment of the present application;

[0015] Figure 2 A schematic diagram of the location of weld cracking when welding a hollow blade without exhaust grooves in some embodiments;

[0016] Figure 3 A schematic diagram of the structure of a centrifugal fan impeller provided according to an embodiment of the present application;

[0017] Figure 4 A schematic diagram of the structure of an air blade of an exhaust slot provided according to some embodiments of the present application;

[0018] Figure 5 for Figure 4 An enlarged schematic diagram of the middle circle A;

[0019] Figure 6 A top view of an air blade with an exhaust slot according to some embodiments of the present application;

[0020] Figure 7 for Figure 6 Enlarged schematic diagram of the middle circle B;

[0021] Figure 8 A schematic diagram of the flow direction of gas on the surface of a hollow blade with exhaust grooves according to some embodiments of the present application.

[0022] Numbers in the figure

[0023] Axle disc 1, hollow blade 2 with exhaust groove, hollow blade 2', wheel cover 3, pressure surface 21, suction surface 22, leading edge 23, trailing edge 24, partition 25, first subspace 261, second subspace 262, sealing position 27, first exhaust groove 31, second exhaust groove 32, weld 41, sealing portion 42. DETAILED DESCRIPTION

[0024] Hereinafter, the present application will be further described based on preferred embodiments with reference to the accompanying drawings.

[0025] In addition, various components in the drawings are enlarged or reduced in size for ease of understanding, but this practice is not intended to limit the scope of protection of the present application.

[0026] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the products of the embodiments of the present application are usually placed when in use, it is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, in the description of the present application, in order to distinguish different units, the words first, second, etc. are used in this specification, but these are not limited by the order of manufacture, nor can they be understood as indicating or implying relative importance, and their names may be different in the detailed description and claims of the present application.

[0027] Figure 1 A hollow blade 2 with an exhaust groove is provided according to an embodiment of the present application. As shown in the figure, the hollow blade 2 with an exhaust groove includes a thin plate-shaped pressure surface 21 and a suction surface 22, and at least one partition plate 25.

[0028] Among them, the pressure surface 21 and the suction surface 22 are connected end to end to form a hollow blade main body structure, and a relatively smoothly curved leading edge 23 and a relatively sharp trailing edge are formed at the connecting position. The partition 25 is fixedly connected to the pressure surface 21 and the suction surface 22 at a vertical or approximately vertical angle, thereby playing a supporting role, which can greatly enhance the structural strength of the hollow blade under high-speed rotation. At the same time, due to the existence of the partition 25, the internal space of the blade main body structure is divided into a first subspace 261 and a second subspace 262 that are independent of each other. Obviously, the two ends of the first subspace 261 are interconnected to form a hollow channel. Similarly, the two ends of the second subspace 262 are interconnected to form a hollow channel.

[0029] In some preferred embodiments, the main blade structure and the partition 25 for improving the structural strength can be integrally formed by metal materials such as aluminum alloy and stainless steel with high strength through cold extrusion. In addition, the partition 25 can also be cut separately and then fixedly welded to the pressure surface 21 and the suction surface 22. Obviously, the number of partitions 25 can be selected according to the width, height and thickness of the main blade structure, such as 1, 2, 3..., so as to enhance the strength of the blade. Accordingly, the number of subspaces separated by the partition 25 can be 2, 3, 4...

[0030] Furthermore, if Figure 1 As shown, in the embodiment of the present application, a first exhaust groove 31 connecting the two sides of the partition is provided at one end of each partition 25, and at the same time, a second exhaust groove 32 is provided at one end of the blade main body structure, so that the internal space of the blade main body structure is connected with the external space, and the first exhaust groove 31 provided on each partition 25 and the second exhaust groove 32 provided on the blade main body structure are oriented in the same direction (that is, the end of the blade main body where the second exhaust groove 32 is located and the end of the partition 25 where each first exhaust groove 31 is located face the same direction), for example, toward Figure 1 As shown in FIG, the first exhaust groove 31 and the second exhaust groove 32 are respectively located at the upward end of the partition plate 25 and the blade main body structure.

[0031] The first exhaust groove 31 and the second exhaust groove 32 are respectively arranged on the same side of the partition plate 25 and the blade main body structure, which can effectively solve the weld cracking problem that occurs during the welding process of the hollow blade. The specific reasons are as follows:

[0032] Generally, the welding sequence of the hollow blades is to first position and weld each hollow blade to the wheel axle disc 1 described later, then position the wheel cover 3 described later and the wheel axle disc 1 welded with the hollow blade, and finally weld the hollow blade to the wheel cover. Due to the presence of the partition 25, when welding the hollow blade and the wheel cover 3, the air is confined to a subspace with a smaller volume. For example, when a hollow blade is welded to the wheel cover 3, the air is confined to a subspace with a smaller volume. Figure 2 When the hollow blade 2' shown is not provided with an exhaust structure, as the welding process shown by the dotted arrow in the figure proceeds, the air in the subspace expands violently and cannot flow to other subspaces, and eventually compresses the uncooled weld at the sealing position 27 of each of the two subspaces, making it impossible to weld firmly or even cause bursting; at the same time, due to the differences in the welding processes of different hollow blades, the position and length of the welds that cannot be welded firmly or even burst are not fixed. Such randomly appearing welds that are not firmly welded seriously affect the consistency of the blade welding effect and greatly increase the complexity of detecting the blade welding quality.

[0033] The hollow blade 2 with exhaust grooves provided in the present application can effectively realize air circulation between the subspaces and between the inside of the hollow blade and the outside world during welding by respectively setting two types of exhaust grooves on the partition plate 25 and the main structure of the blade, thereby effectively alleviating the above-mentioned weld cracking problem. The welding process of the hollow blade 2 with exhaust grooves is described in detail below.

[0034] Figure 3 The schematic diagram of the structure of the centrifugal fan impeller manufactured using the hollow blades 2 with exhaust slots provided in the present application is as follows: Figure 3 As shown, the centrifugal fan impeller includes a wheel shaft disc 1 and a wheel cover 3, and a plurality of hollow blades 2 with exhaust grooves, wherein the wheel shaft disc 1 and the wheel cover 3 are coaxially arranged at intervals, and the plurality of hollow blades 2 with exhaust grooves are distributed between the wheel shaft disc 1 and the wheel cover 3 at intervals along the circumferential direction, and the two ends of each hollow blade with exhaust grooves are fixedly connected to the wheel shaft disc 1 and the wheel cover 3 by welding, and a weld 41 is formed. At the same time, as shown in FIG. Figure 3 As shown, a sealing portion 42 is also airtightly provided at the second exhaust slot 32 of each hollow blade 2 with an exhaust slot, so as to achieve airtight isolation between the internal space of the entire blade main structure and the outside world. In some preferred embodiments, the centrifugal fan impeller can be manufactured by the following process:

[0035] The first step is to position the wheel axle disc 1 and the hollow blades 2 with exhaust grooves, so that the first exhaust groove 31 and the second exhaust groove 32 of each hollow blade 2 with exhaust grooves are both facing the side of the wheel cover 3, and then weld one end of the blade main structure facing the wheel axle disc 1 to the wheel axle disc 1, so that the blade main structure is fixedly connected to the wheel axle disc 1 in an airtight manner;

[0036] The second step is to position the wheel cover 3 and the wheel axle disc 1 to which the hollow blades 2 with exhaust grooves have been welded, and then weld and fix one end of the blade main structure facing the wheel cover 3 to the wheel cover 3;

[0037] In the third step, a sealing portion 42 is provided at the second exhaust groove 32 to ensure that the blade main structure is fixedly connected to the wheel cover 3 in an airtight manner.

[0038] In some specific embodiments, the first step and the second step can be implemented using a conventional welding process, wherein the welding process parameters include: the current intensity of the electric welding machine is 150-160A, the arc voltage is 14-16V, the welding speed is 140-160mm / min, and the flow rate of the arc shielding gas is 14-18L / min.

[0039] In some specific embodiments, the third step can be achieved by the blocking welding process to achieve the setting of the sealing portion 42, and the blocking welding process parameters include: the current intensity of the electric welder is 170-180A, the arc voltage is 16-18V, the welding speed is 150-170mm / min, and the flow rate of the arc shielding gas is 14-18L / min. Since the sealing treatment of the second exhaust groove 32 is carried out after the other parts of the hollow blade 2 with the exhaust groove have been welded, at this time, the various spaces inside the blade are interconnected through the first exhaust groove 31, and the inside of the blade is connected to the outside air only through the second exhaust groove 32. In the process of blocking welding the second exhaust groove 32, the current intensity, voltage and welding speed used for blocking welding are appropriately improved compared with the welding of other parts of the blade, so that the position of the second exhaust groove 32 can be quickly sealed, avoiding continuous welding at the second exhaust groove 32, so that the temperature of the internal gas of the blade near the second exhaust groove 32 continues to rise, and a large air pressure is generated at the blocking welding position, resulting in the problem that the blocking welding cannot be firmly achieved, and the sealing effect of the place is effectively improved.

[0040] In some preferred embodiments, before plugging the second exhaust groove 32, the hollow blade 2 with the exhaust groove that has completed the second step can be left to stand for a period of time to allow the temperature of the blade surface and the air near it to drop. After the air pressure inside the blade is consistent with the external air pressure, plugging can be performed to further improve the sealing effect of the plugging.

[0041] Figure 4 The figure shows the arrangement positions of the first exhaust groove 31 and the second exhaust groove 32 in some preferred embodiments. Figure 5 right Figure 4 The circle A in the figure is enlarged. Figure 6 for Figure 4 A top view of the embodiment shown, Figure 7 right Figure 6 Circle B in FIG. 1 is shown enlarged.

[0042] like Figures 4 to 7As shown, the second exhaust groove 32 can be arranged on the suction surface 22, and its distance relative to the trailing edge 24 is smaller than its distance relative to the leading edge 23. At the same time, the slotting direction of the second exhaust groove 32 is inclined from the trailing edge 24 to the leading edge 23, that is, the distance of the opening of the second exhaust groove 32 on the outer side of the suction surface 22 relative to the trailing edge 24 is smaller than the distance of the opening on the inner side of the suction surface 22 relative to the trailing edge 24, and its outer opening is closer to the trailing edge of the blade hollow 2 than the inner opening.

[0043] The second exhaust groove 32 is arranged on one side of the suction surface 22, which helps to reduce the strength requirement for the airtight connection between the sealing portion and the second exhaust groove 32: Figure 8 As shown, when the impeller rotates, the airflow mainly applies pressure to the blade on the pressure surface 21 side, and the gas pressure on the suction surface 22 is relatively small. Therefore, an exhaust groove is provided on the suction surface 22, and there is no need to additionally ensure the connection strength of the sealing part. In addition, the inclined slotting direction has a good shielding effect on the airflow, which can prevent the airflow from entering the interior of the blade along the slotting direction when the sealing part becomes loose or falls off.

[0044] In some preferred embodiments, the groove width and groove depth of the first exhaust groove 31 and the second exhaust groove 32 are much smaller than the height of the blade main body structure. For example, the groove width and groove depth of the first exhaust groove 31 and the second exhaust groove are less than 1 / 10 (or 1 / 20) of the height of the blade main body. Furthermore, since the pressure balance of the gas in each subspace can be achieved through the first exhaust groove 31, in some other preferred embodiments, the groove width D of the second exhaust groove 32 is smaller than the groove width of the first exhaust groove 31, and the groove depth of the second exhaust groove 32 is also smaller than the groove depth of the first exhaust groove 31, that is, the airflow flow section of the first exhaust groove 31 is larger than the airflow flow section of the second exhaust groove 32, so as to preferentially achieve the air pressure balance inside the blade.

[0045] In addition, in other preferred embodiments, the groove width and groove depth of the second exhaust groove 32 are smaller than the thickness of the blade main structure (i.e., the thickness of the pressure surface and / or suction surface surrounding the blade main structure). While ensuring the overall exhaust volume of the second exhaust groove 32, the size of the second exhaust groove 32 is further reduced, which can effectively avoid the groove width or depth being too large, which will have a significant impact on the connection strength between the blade main structure and the wheel cover 3.

[0046] The above is a detailed introduction to the specific implementation methods of the present application. For those skilled in the art, several improvements and modifications may be made to the present application without departing from the principles of the present application. These improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A hollow blade with an exhaust groove, comprising a thin plate-shaped pressure surface and a suction surface, and at least one partition, wherein the pressure surface and the suction surface enclose a hollow blade main structure, and the partition divides the internal space of the blade main structure into a plurality of subspaces that are independent of each other and connected at both ends, characterized in that: A first exhaust groove connecting the two sides of the partition is arranged at the end of each partition, and a second exhaust groove connecting the inside and outside of the blade main body structure is arranged at the end of the blade main body structure, and the end of the blade body where the second exhaust groove is located and the end of the partition where the first exhaust groove is located face the same direction.

2. The hollow blade with exhaust groove according to claim 1, characterized in that: The second exhaust groove is arranged on the suction surface, and the distance between the second exhaust groove and the trailing edge of the blade main body structure is smaller than the distance between the second exhaust groove and the leading edge of the blade main body structure.

3. The hollow blade with exhaust groove according to claim 2, characterized in that: The second exhaust groove obliquely penetrates the suction surface, and the distance between the opening of the second exhaust groove on the outer side of the suction surface and the trailing edge is smaller than the distance between the opening of the second exhaust groove on the inner side of the suction surface and the trailing edge.

4. The hollow blade with exhaust groove according to claim 1, characterized in that: The groove width and groove depth of the first exhaust groove and the second exhaust groove are much smaller than the height of the blade main body structure.

5. The hollow blade with exhaust grooves according to claim 4, characterized in that: The groove width of the second exhaust groove is smaller than the groove width of the first exhaust groove, the groove depth of the second exhaust groove is smaller than the groove depth of the first exhaust groove, and, The groove width and groove depth of the second exhaust groove are both smaller than the thickness of the blade main body structure.

6. A centrifugal fan impeller, comprising a wheel axle disc and a wheel cover, wherein the wheel axle disc and the wheel cover are coaxially arranged and spaced apart, characterized in that: Also includes: A plurality of hollow blades with exhaust grooves according to claim 1, and a sealing portion corresponding to the second exhaust groove of each of the hollow blades with exhaust grooves; A plurality of hollow blades with exhaust grooves are distributed between the wheel axle disc and the wheel cover at intervals along the circumferential direction, and two ends of each hollow blade with exhaust grooves are fixedly connected to the wheel axle disc and the wheel cover respectively; Each sealing portion is airtightly arranged at the second exhaust groove of the corresponding hollow blade with the exhaust groove.

7. The centrifugal fan impeller according to claim 6, characterized in that: The second exhaust groove of each hollow blade with exhaust groove faces one side of the wheel cover.

8. The centrifugal fan impeller according to claim 7, characterized in that: The hollow blade with the exhaust groove is fixedly connected to the wheel axle disk and the wheel cover by a welding process, and the sealing part is fixedly connected between the second exhaust groove and the wheel cover in an airtight manner by a blocking welding process.

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