Method for producing shrouded fan wheel, shrouded fan wheel and fan
By designing the geometry of the rear edge of the shield ring with the shield fan wheel and setting only a radial enlargement in part of the circumference, the high cost and rapid wear problems caused by the use of slider tools in the prior art are solved, and cheap and efficient manufacturing using slider tools are achieved.
Patent Information
- Application Number
- CN202411553175.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-20
- Filing Date
- 2024-11-01
- Publication Date
- 2025-05-20
AI Technical Summary
The existing fan wheel with shield requires the use of injection molding tools with sliders during the manufacturing process, resulting in high cost of tools and rapid wear, which in turn increases the cost of a single piece.
By designing the rear edge geometry of the shield ring, it can be manufactured using slider-free injection molding tools. The specific implementation method is to set a radial enlargement at the rear edge of the shield ring only at the partial circumference section to avoid surrounding the entire circle and ensure that there are no side recesses.
Using sliderless tools can significantly shorten manufacturing cycles, reduce tool costs, extend tool life, and achieve inexpensive and efficient manufacturing with shield fan wheels.
Smart Images
Figure CN120020388A_ABST
Abstract
Description
Field of the Invention
[0001] The present invention relates to a method for manufacturing a shrouded fan wheel. The present invention also relates to a shrouded fan wheel manufactured according to the method, and a fan having at least one such shrouded fan wheel, in particular a viscous fan in a motor vehicle. Background Art
[0002] Fans with shrouded fan wheels have been widely used in the field of motor vehicle manufacturing. Among them, compared with unshrouded fan wheels, the main advantage of such shrouded fan wheels is that due to the co-rotation of their shroud rings, these shrouded fan wheels are less sensitive to the size of the air gap between the outer diameter of the shrouded fan wheel and the inner diameter of, for example, an intake nozzle. On the contrary, in an unshrouded fan wheel, the efficiency decreases as the air gap between the intake nozzle and the fan wheel increases, and unpleasant flow noise is also generated. However, when using a fan wheel in an internal combustion engine, there is a target conflict between, on the one hand, making the air gap between the fan wheel and the intake nozzle as small as possible to achieve the highest possible efficiency and, on the other hand, making the air gap as large as possible to reliably avoid collisions caused by vibrations between the fan wheel and the intake nozzle. Therefore, especially in the field where fans are used in internal combustion engines, shrouded fan wheels will provide considerable advantages.
[0003] In addition, it has also been shown that a shrouded fan wheel having a shroud ring that is radially widened in the flow direction (i.e., from the front edge to the rear edge) has aerodynamic advantages because this shroud ring shape results in an increase in volume flow rate and thus higher efficiency.
[0004] However, in such a shrouded fan wheel having a shroud ring that is radially widened in the flow direction, the disadvantage is that this shrouded fan wheel can only be manufactured using an injection molding tool with sliders, where such an injection molding tool with sliders means higher tool costs and faster wear, resulting in overall higher unit costs for such shrouded fan wheels. Summary of the Invention
[0005] Therefore, the problem to be solved by the present invention is to describe a method for manufacturing an efficient and smoothly operating shrouded fan wheel that is both inexpensive and easy to manufacture.
[0006] According to the present invention, this problem is solved by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.
[0007] The overall concept on which the present invention is based is to describe a method for manufacturing a shrouded fan wheel, wherein the trailing edge geometry of the shroud ring of such a shrouded fan wheel is configured such that the shrouded fan wheel can be manufactured using a sliderless tool (such as a sliderless injection molding tool). The shrouded fan wheel to be manufactured herein has fan blades starting from a hub and a shroud ring firmly connected to the fan blades at the ends of the fan blades remote from the hub, wherein the shroud ring has a radially expanding portion and a portion without a radially expanding portion at the trailing edge. At the radially expanding portion, the outer diameter of the shroud ring at the trailing edge is greater than the outer diameter of the shroud ring at the leading edge. At the portion without a radially expanding portion, the outer diameter of the shroud ring at the trailing edge is comparable to the outer diameter of the shroud ring at the leading edge. The shroud ring is thus configured such that the entire shrouded fan wheel can be integrally formed using a sliderless injection molding tool. The shroud ring is manufactured without side recesses herein, so that the above-mentioned sliderless injection molding tool can be used. According to the present invention, this is achieved by implementing the radially expanding portion of the trailing edge of the shroud ring of the shrouded fan wheel not in a full circle but only in individual circumferential segments, which are interrupted by portions without a radially expanding portion. These portions without a radially expanding portion represent contact areas where the blade trailing edges of the respective fan blades touch the shroud ring. Compared with a tool with a slider, using a sliderless tool can achieve a significantly shorter manufacturing cycle and also only requires significantly reduced tool costs, and wherein, compared with a tool with a slider, the service life of such a sliderless tool is also significantly increased due to reduced wear. In summary, through the implementation of the shrouded fan wheel and the concomitant use of a sliderless tool that can be achieved, a significantly reduced manufacturing cost of the shrouded fan wheel can be realized.
[0008] The present invention is also based on the following overall concept to describe a shrouded fan wheel manufactured by the method described in the above paragraph. This makes it possible to transfer the advantages described in the method for manufacturing a shrouded fan wheel to the shrouded fan wheel. Specifically, these advantages are particularly reflected in inexpensive and simple manufacturing because a sliderless injection molding tool can be used for manufacturing, which requires less tool cost, has lower wear, and allows a shorter manufacturing cycle, which generally results in a more inexpensive manufacturing of the shrouded fan wheel. In addition, such a shrouded fan wheel having a radially expanding portion arranged at the trailing edge has higher efficiency, whereby a higher volume flow can be achieved with the same power.
[0009] In an advantageous improvement of the shrouded fan wheel according to the present invention, its shroud ring is cylindrically configured at the leading edge. This makes it possible for the shrouded fan wheel to operate in an intake nozzle using the leading edge, whereby a high volume flow and thus also high efficiency can be achieved.
[0010] In a further advantageous embodiment of the shrouded fan wheel according to the invention, the outer radius of the shroud ring at its trailing edge varies in the circumferential direction. Different from the shrouded fan wheels known from the prior art, which continuously expand radially at the trailing edge of the shroud ring and thus cannot be manufactured using a sliderless tool, by varying the outer radius of the shroud ring at its trailing edge in the circumferential direction, a sliderless injection molding tool can be used to manufacture the shrouded fan wheel according to the invention, which will significantly reduce the manufacturing cost.
[0011] In a particularly preferred embodiment of the shrouded fan wheel according to the invention, the fan blades are integrally connected to the shroud ring with a blade leading edge and a blade trailing edge, wherein the shroud ring is cylindrical in the contact area with the blade leading edge of each respective fan blade and in the contact area between the blade trailing edge of each respective fan blade and the shroud ring. By this technique according to the invention, side recesses that would otherwise occur in the contact area between the blade trailing edge and the shroud ring can be avoided, which for the first time enables the use of a sliderless tool.
[0012] In a further advantageous embodiment of the shrouded fan wheel according to the invention, such an enlargement is respectively arranged at the trailing edge of the shroud ring in the circumferential direction between the two blade trailing edges of two adjacent fan blades. Thus, between two blade trailing edges adjacent in the circumferential direction, the trailing edge of the shroud ring expands radially outwards, whereby the aerodynamic performance and efficiency of the shrouded fan wheel according to the invention can be improved. By retracting the outer radius in the contact area between the respective blade trailing edge of the fan blade and the shroud ring to the radius of the leading edge of the shroud ring, side recesses that would make a slider necessary can be avoided there.
[0013] In a particularly preferred embodiment of the shrouded fan wheel according to the invention, the radial enlargement of the shroud ring extends at most over 50% of the axial height of the shrouded fan wheel. Thereby, it is possible to insert the shrouded fan wheel according to the invention into the intake nozzle of a fan, especially a viscous fan, by half, and thus achieve a particularly high fan efficiency.
[0014] Suitably, the hub of the shrouded fan wheel is configured in a pot shape. By this pot-shaped configuration, significant resource savings and significant weight savings can be achieved, which again significantly reduces the manufacturing cost of the shrouded fan wheel and enables the use of lighter bearings.
[0015] In a particularly preferred embodiment, reinforcing ribs extending in the axial direction (i.e., in the flow direction) are constructed on the inner side of the pot-shaped hub, and these reinforcing ribs taper from the hub bottom towards the hub edge on the hub wall. Thus, the reinforcing ribs are arranged in a triangular shape between the hub wall and the hub bottom and taper along the hub wall from the hub bottom towards the hub edge. With such reinforcing ribs, the entire hub itself can be made thinner-walled, thereby achieving weight advantages and cost advantages due to less material input.
[0016] In a further embodiment of the shrouded fan wheel according to the invention, the inner side of the shroud ring also expands in the region of the radial expansion, or is cylindrical and thus has no radial expansion. A great advantage provided by the first embodiment here is that the first embodiment can be manufactured with significantly less material, thus more inexpensively and with a reduced weight. In the second embodiment, wherein the inner side of the shroud ring is cylindrically configured in the region of the radial expansion, that is to say the shroud ring has the same inner diameter at the rear edge and at the front edge, the region between the inner side of the shroud ring and the outer side of the expansion is filled with plastic. Although this is not as advantageous in terms of resource input and weight as the first solution, the second embodiment can still enable the use of a sliderless injection molding tool, and thus a high-efficiency shrouded fan wheel can still be manufactured at a relatively low unit cost.
[0017] The invention is also based on the general concept that at least one of the shrouded fan wheels described in any one of the preceding paragraphs is provided on a fan, in particular on a viscous fan of a motor vehicle, wherein the shrouded fan wheel is arranged in the intake nozzle by means of its front edge of the shroud ring. Thus, the fan has, for example, a cooler and the described fan, which has an intake nozzle that is connected to the cooler at one end and, at the other end, the shrouded fan wheel according to the invention is rotatably arranged in the intake nozzle by means of its front edge. Thereby, a fan that is not only inexpensive but also highly efficient is achieved.
[0018] Other important features and advantages of the invention result from the dependent claims, the drawings and the description of the invention in conjunction with the drawings.
[0019] It should be understood that the features mentioned above and to be explained below can be used not only in the combinations separately described, but also in other combinations or individually, without departing from the scope of the invention. The separately marked components mentioned above and to be explained below of an upper unit such as a device, equipment or component can form separate components of the unit, or can also be integrated regions or sections of the unit, even if this is shown otherwise in the drawings in this regard. Description of the Drawings
[0020] Preferred embodiments of the present invention are shown in the accompanying drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.
[0021] wherein schematically:
[0022] Figure 1 shows an oblique view of a shrouded fan wheel according to the present invention;
[0023] Figure 2 shows a front view of a shrouded fan wheel according to the present invention;
[0024] Figure 3 shows a detailed front view of a shrouded fan wheel according to the present invention;
[0025] Figure 4 shows a sectional view through a shrouded fan wheel according to the present invention in an alternative embodiment, wherein there is a material accumulation portion between the inner side of the shroud ring and the radially enlarged portion;
[0026] Figure 5 shows an additional sectional view through the shrouded fan wheel according to the present invention in the region between two fan blades;
[0027] Figure 6 shows a sectional view along the trailing edge of the fan blade. Detailed Description
[0028] According to Figures 1 to 6 , the shrouded fan wheel 1 according to the present invention has a hub 2, fan blades 3 extending outwardly from the hub, and a shroud ring 4 that surrounds the fan blades 3 at the ends of the fan blades remote from the hub and rotates with the shrouded fan wheel 1. If the shrouded fan wheel 1 rotates about an axis 5 in the rotational direction 6, an air flow 8 can be induced via the shrouded fan wheel 1 according to the present invention.
[0029] The shroud ring 4 has a leading edge 9 and a trailing edge 7, and each fan blade 3 has a blade leading edge 10 and a blade trailing edge 11, respectively.
[0030] The shroud ring 4 is cylindrically formed at the leading edge 9 and can thus be inserted into Figure 1 the intake nozzle 12 of the fan 13 shown only. Each fan blade 3 has a suction side 14 and a pressure side 15 here.
[0031] At the trailing edge 7, the shrouded fan wheel 1 according to the present invention now has a radially enlarged portion 16, which improves the aerodynamic performance of the shrouded fan wheel 1 according to the present invention and results in an increase in volume flow rate and thus an improvement in efficiency. Therefore, the shroud ring 4 widens in the region of the radially enlarged portion 16 in the flow direction 8.
[0032] Nevertheless, in order to manufacture the shrouded fan wheel 1 according to the invention by injection molding inexpensively and simply, the radial enlargements 16 are arranged only between the trailing edges 11 of two adjacent blades in the circumferential direction 17. However, at the respective trailing edges 11 of the blades, there are still portions 18 where no radial enlargements 16 are arranged, so that at this portion 18, the trailing edge 7 has the same radius as the leading edge 9, which can also be clearly seen from Figure 6 this. At the portion 18, since there is no radial enlargement 16, the shroud ring 4 deforms inwards again. The transition or reverse transition from the radial enlargement 16 to the portion 18 is achieved here without any jumps or bends. The outer radius of the trailing edge 7 of the shroud ring 4 of the shrouded fan wheel 1 according to the invention varies in the circumferential direction 17 and is greater in the region of the radial enlargement 16 than at the portion 18 corresponding to the outer radius of the leading edge 9. At the radial enlargement 16, the shroud ring 4 has a greater outer diameter at the trailing edge 7 than at the leading edge 9, while at the portion 18 without the radial enlargement 16, the shroud ring has an outer diameter at the trailing edge 7 that is equivalent to the outer diameter at the leading edge 9 of the shroud ring 4.
[0033] Each fan blade 3 is connected to the shroud ring 4 by means of its blade leading edge 10 and its blade trailing edge 11, wherein the shroud ring 4 is formed cylindrically both in the contact region with the blade leading edge 10 and in the contact region with the blade trailing edge 11, so that at this portion 18, the outer radius of the leading edge 9 of the shroud ring 4 is at least substantially equivalent to the outer radius of the trailing edge 7.
[0034] Looking at the enlargements 16 according to Figures 4 to 6 the invention, it can be seen that these enlargements extend at most over 50% of the axial height H of the shrouded fan wheel 1 according to the invention. Therefore, the shroud ring 4 has a constant diameter over the 50% occupied towards the leading edge 9 and thus has a cylindrical shape and can be inserted into the intake nozzle 12.
[0035] Looking further at the shrouded fan wheel 1 according to the invention, it can be seen that its hub 2 is formed in a pot shape, which has a hub bottom 19 and a hub wall 20 connected thereto, and the hub wall terminates at the hub edge 21. This embodiment offers the great advantage that the hub 2 itself can be made of relatively little material and is thus not only constructed lightly but also resource-saving and inexpensive. As Figures 4 to 6As shown, on the inner side 22 of the pot-shaped hub 2, i.e., on the inner side of the hub wall 20, reinforcing ribs 23 can be arranged in the axial direction, i.e., extending parallel to the axis 5. The reinforcing ribs taper from the hub bottom 19 along the hub wall 20 to the hub edge 21. Such reinforcing ribs 23 can achieve a further reduction in the material of the hub 2, thereby making the entire shrouded fan wheel 1 lighter again, made of less material and thus more cheaply, and in addition, only smaller or lighter bearings are required.
[0036] Observation Figure 4 and Figure 6 It can be seen that in the shrouded fan wheel 1 according to the invention, the inner side 24 of the shroud ring 4 on the suction side 14 of the respective fan blade 3 is cylindrical, while the shroud ring expands outward in the region of the radial expansion 16 in the flow direction of the air flow 8 on the pressure side 15 (see Figure 5 ). Purely theoretically, if the region 25 located radially between the inner side 24 and the expansion 16 is solidly implemented, the shrouded fan wheel 1 according to the invention could also be manufactured using a sliderless injection molding tool, as shown in Figure 4 . However, such a solid implementation would result in material accumulation in the region 25, whereby the shrouded fan wheel 1 would not only be heavier, but also require more resource input. In summary, therefore, in the sense of the present invention, it is feasible to manufacture such a shrouded fan wheel 1, but it is not preferred.
[0037] Generally, the shrouded fan wheel 1 according to the invention can be manufactured, for example, by injection molding in a sliderless injection molding tool. Purely theoretically, manufacturing by die casting in a sliderless die casting tool is also considered. Aluminum can be used in particular. As a further alternative, the shrouded fan wheel 1 according to the invention can also be manufactured by ceramic injection molding in a sliderless ceramic injection molding tool. Manufacturing the shrouded fan wheel 1 according to the invention with plastic offers the great advantage that it can not only be manufactured lightly, but also inexpensively. The lightweight implementation of the shrouded fan wheel 1 can also enable a weight-reducing implementation of the fan 13 equipped with it, and also enable the use of smaller, lighter and cheaper bearings to support the shrouded fan wheel 1.
[0038] In summary, due to the special geometry of the shroud ring 4 of the shrouded fan wheel 1 according to the invention, the shrouded fan wheel is manufactured using a sliderless injection molding tool, which is significantly cheaper compared to an injection molding tool equipped with a slider, because the sliderless injection molding tool requires lower tool costs and is moreover more wear-resistant. A shorter manufacturing cycle is also possible in a sliderless injection molding tool.
[0039] However, since the reduction in extent is only in the region of part 18 with respect to the radially expanding part 16, the advantages of the aerodynamic performance associated with such an expanding part 16 can still be achieved, such as a higher volume flow rate and the associated higher efficiency.
Claims
1. A method for manufacturing a shrouded fan wheel (1), - in, The shrouded fan wheel (1) has fan blades (3) extending from a hub (2) and a shroud ring (4) surrounding the fan blades (3) at the ends of the fan blades away from the hub and rotating together with the shrouded fan wheel (1). - wherein the shroud ring (4) has a radially enlarged portion (16) and a portion (18) without the radially enlarged portion (16) at the rear edge (7), - wherein the shrouded fan wheel (1) is produced by means of injection molding.
2. The method according to claim 1, It is characterized in that The shrouded fan wheel (1) is manufactured using a slider-less injection molding tool.
3. A shrouded fan wheel (1), wherein the shrouded fan wheel is manufactured according to the method according to claim 1 or 2.
4. The shrouded fan wheel according to claim 3, It is characterized in that The shroud ring (4) is cylindrical at the front edge (9) of the shrouded fan wheel (1).
5. The shrouded fan wheel according to claim 3 or 4, It is characterized in that The fan blade (3) is connected to the shroud ring (4) with a blade front edge (10) and a blade rear edge (11), wherein the shroud ring (4) is cylindrical in the contact area with the blade front edge (10) and in the contact area with the blade rear edge (11).
6. The shrouded fan wheel according to claim 5, It is characterized in that An enlargement (16) is arranged at the rear edge (7) of the shroud ring (4) in the circumferential direction (17) between two blade rear edges (11) of two adjacent fan blades (3).
7. A shrouded fan wheel according to any one of claims 3 to 6, It is characterized in that The radial expansion (16) of the shroud ring (4) extends over at most 50% of the axial height (H) of the shrouded fan wheel (1).
8. A shrouded fan wheel according to any one of claims 3 to 7, It is characterized in that The hub (2) is designed in a pot-shaped manner.
9. The shrouded fan wheel according to claim 8, It is characterized in that Reinforcing ribs (23) are formed on the inner side (22) of the pot-shaped hub (2), which ribs taper from the hub base (19) on the hub wall (20) toward the hub edge (21).
10. A fan (13), in particular a viscous fan in a motor vehicle, having an air intake nozzle (12) and at least one shrouded fan wheel (1) according to any one of claims 3 to 9, wherein the shrouded fan wheel is arranged with a front edge (9) of its shroud ring (4) in the air intake nozzle (12).