fan wheel and fan

Abstract

The present invention relates to a fan wheel (1) for a fan (2) with at least two fan blades (3) which have a wave- or tooth-like contour line (5) with projections (6) and recesses (7) on a respective blade leading edge (4). The essential aspect of the invention is that a ratio of a height A of the projections (6) to a wavelength W from one wave trough (9) to another wave trough (9) is defined as follows. A / W ≥ 1. This allows for the creation of an efficient and quiet fan wheel (1).

Description

[0001] The present invention relates to a fan wheel for a fan with at least two fan blades, according to the preamble of claim 1. The invention also relates to a fan, in particular for an air conditioning unit of an electric vehicle, with such a fan wheel.

[0002] From US 11035233 B2, a generic fan wheel for a fan with at least two fan blades is known, which has a wave- or tooth-like contour line with projections and recesses on a respective blade leading edge.

[0003] From WO 2013 / 180296 A1, another fan wheel of the same type for a fan is known.

[0004] Fans are used in a variety of ways in motor vehicles, especially battery electric vehicles (BAVs), with particular attention paid to their efficiency and noise emissions. In electric vehicles, efficiency directly impacts the power consumption of a fan motor and thus the vehicle's range. Noise emissions are also of greater importance in electric vehicles, as they are significantly quieter than vehicles powered by internal combustion engines. Fans in electric vehicles are also used, in particular, for thermal management modules that regulate the temperature, especially the cooling, of the vehicle battery.Temperature control of such a vehicle battery is particularly important because operating the vehicle battery within an optimal temperature range not only enables a greater range, but also reduces charging time through cooling.

[0005] Fan wheels with fan blades are already known from the prior art, which have a wave- or tooth-like contour line on a blade leading edge located in the direction of rotation or on a blade trailing edge directed against the direction of rotation, which are used as a particularly effective measure for noise reduction.

[0006] However, a disadvantage of the fan wheels known from the prior art is that the selected protrusions or recesses on the wave- or tooth-like contour line at a blade leading edge or a blade trailing edge do not have optimal geometric dimensions and therefore cannot significantly increase the efficiency of the fan blade and thus indirectly of the fan, without having to accept significantly higher noise emissions.

[0007] The present invention therefore deals with the problem of providing an improved or at least an alternative embodiment for a fan wheel of the generic type, by means of which in particular the disadvantages known from the prior art can be overcome.

[0008] This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0009] The present invention is based on the general concept of designing projections and recesses of a wave- or zigzag-shaped contour line arranged on a blade leading edge with respect to a height A of the projections and a wavelength W in such a way as to enable a significant increase in efficiency without having to accept a significant increase in noise emissions. This is achieved by defining, according to the invention, a ratio of the height A of the projections to a wavelength W measured from recess to recess, i.e., from wave trough to wave trough, as follows: A / W ≥ 1. With such a selected ratio, both efficient and low-noise operation of a fan equipped with such a fan wheel is possible.A further increase in the fan's efficiency, without increasing noise emissions, can be achieved by selecting a ratio of the height A of the projections to the wavelength W from wave trough to wave trough A / W ≥ 1.5, particularly preferably A / W ≥ 2. An upper limit of approximately 4 is typically used for the ratio of the height A of the projections to the wavelength W from wave trough to wave trough. A higher ratio might compromise the stability of the individual projections. Thus, with a fan wheel designed according to the invention, the fan's efficiency can be significantly increased without increasing noise emissions.

[0010] In a further advantageous embodiment of the fan wheel according to the invention, a height A corresponds to at least 10% of the flow-through length BL of the fan blade, preferably at least 15% of the flow-through length BL of the fan blade, and most preferably at least 20% of the flow-through length BL of the fan blade. The flow-through length BL selected in each case can, for example, be chosen depending on the fan blades.

[0011] Advantageously, the contour line extends only to approximately 70%, preferably only to approximately 50%, of the radial length of the fan blade. This means, for example, that the contour line begins radially inward at or spaced apart from a hub of the fan wheel and ends at approximately 70% of the radial length of the fan blade, so that the contour line does not extend outwards across the entire fan blade. Tests have shown that the inventive effect of the contour line in increasing efficiency and reducing noise emissions is limited to certain rotational speeds. Therefore, the arrangement of such a contour line is not advantageous on a radially outer region of the fan blade where higher rotational speeds occur during operation.

[0012] In a further advantageous embodiment of the fan wheel according to the invention, the contour line begins at the hub or at a distance from it. Both embodiments offer advantages with regard to manufacturing, particularly if the fan wheel is, for example, designed as a plastic injection-molded part.

[0013] It is advantageous to have at least one circumferential projection inclined relative to the fan blade. The major advantage of such an inclination of the projection relative to the fan wheel is that the projection, with its tip or free end, is always aligned in the direction of rotation and not at an angle to it.

[0014] In a particularly preferred embodiment of the fan wheel according to the invention, at least one projection has a greater thickness than the rest of the fan blade. Such a thicker projection can blend seamlessly into the fan blade, thereby achieving aerodynamic advantages and avoiding stress concentrations due to kinks or steps.

[0015] In a particularly preferred embodiment of the fan blade according to the invention, the projections are made of a different material than the fan blade. For example, the projections could be made of a metal strip, while the fan blade is made of plastic, so that in this case the fan blade and the projections could be formed as a two-component injection-molded plastic part. By making the projections of metal, for example, they can be designed with a comparatively high aspect ratio (A / W) without any risk of deformation of the individual projections during operation of the fan wheel.

[0016] Advantageously, the fan wheel can also have a wave- or zigzag-like contour line with projections and recesses on its trailing edge. By also arranging a wave- or zigzag-like contour line with projections and recesses on the trailing edge of the blade, both efficiency can be further increased and noise emissions further reduced. It is conceivable that the wave- or zigzag-like contour line arranged on the trailing edge of the blade is designed analogously to the wave- or zigzag-like contour line according to the invention arranged on the leading edge of the blade.

[0017] By connecting two adjacent projections, the strength of the projections can be increased, thereby creating a particularly stiff and especially quiet fan wheel in operation.

[0018] The present invention is further based on the general concept of equipping a fan with a fan wheel according to the invention as described in the preceding paragraphs, thereby transferring the advantages described with respect to the fan wheel according to the invention to the fan. Specifically, these advantages lie in particular in the increased efficiency of such a fan combined with low noise emissions. This allows the fans according to the invention to be used, especially in electric vehicles, which are particularly sensitive to noise. The improved efficiency also enables energy-saving operation of the fan, which is also a great advantage when used in electric vehicles.

[0019] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings and the associated description of the figures based on the drawings.

[0020] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention as defined by the claims. Components of a higher-level unit, such as a device, apparatus, or arrangement, mentioned above and those to be mentioned below, which are designated separately, can form separate parts or components of this unit or be integral areas or sections of this unit, even if this is depicted differently in the drawings.

[0021] Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0022] They show, schematically, Fig. 1 a view of a fan wheel according to the invention of a fan according to the invention, Fig. 2 a detailed representation from Fig. 1.

[0023] According to the Fig. 1 has a fan wheel 1 according to the invention of a fan 2 according to the invention, for example for an electric vehicle not shown in detail, at least two fan blades 3 (compare also Fig. 2) which have a wavy or jagged contour line 5 with projections 6 and recesses 7 on each leading edge 4 of the leaf. The direction of the leading edge 4 of the leaf is aligned in the direction of rotation towards 8.

[0024] According to the Fig. 1 The fan wheel 1 according to the invention has a total of nine fan blades 3, whereby such a fan wheel 1 according to the invention may also have fewer or more such fan blades 3.

[0025] According to the invention, a ratio of a height A (compare Fig. 2) the projections 6 to a wavelength W from a wave trough 9 to an adjacent wave trough 9 or from a wave crest 10 to an adjacent wave crest 10 (compare Fig. 2) defined as follows: A / W≥1.

[0026] The relatively slim projections 6, which have a large height A, enable not only efficient but also relatively quiet operation of the fan wheel 1, which is particularly advantageous when used in electric vehicles, which are considered to be particularly sensitive to noise.

[0027] The height A of the projections 6 can vary along the contour line 5.

[0028] In order to further increase efficiency without having to accept a significant increase in noise emissions, the ratio of the height A of the projections 6 to a wavelength W from a wave trough 9 to an adjacent wave trough 9 or from a wave crest 10 to an adjacent wave crest 10 can also be ≥ 1.5 or ≥ 2.0.

[0029] If one considers the projections 6 and in particular their free end, i.e. the wave crest 10, one can, according to the Fig. 2. Recognize that the wave crest 10, i.e., the tip, is rounded. Of course, pointed wave crests 10 or angular wave crests 10 are also conceivable.

[0030] The height A of the projections 6 corresponds to at least 10% of the flow-over length BL of the fan blade 3 (compare Fig. 1), preferably at least 15% of the flow-through length BL, particularly preferably at least 20% of the flow-through length BL of the fan blade 3. The ratio of the height A of the projections 6 to the flow-through length BL of the fan blades 3 can further influence both the efficiency and the noise generation during the operation of the fan wheel 1.

[0031] If one considers the Fig. Further, it can be seen that the contour line 5 extends only to approximately 70% of the radial length L of the fan blade 3. The contour line 5 is therefore located on an inner region of the fan blade 3, where a lower circumferential speed is present during operation of the fan 2. Particularly preferably, the contour line 5 can also extend only to approximately 50% of the radial length L of the fan blade 1.

[0032] The fan blades 3 extend from a hub 11 to an outer ring 12 and are preferably integrally connected to both the hub 11 and the ring 12. The contour line 5, in turn, can be arranged at a distance from or begin at the hub 11, or it can be located directly at the hub 11.

[0033] If one considers the Fig. 1 and Fig. 2 further, it can be seen that the projections 6 are inclined in the circumferential direction, i.e. in the direction of rotation 8, relative to the fan blade 3, resulting in an improved aerodynamic ratio.

[0034] Furthermore, at least one projection 6 can have a greater thickness than the rest of the fan blade 3, whereby such a thickened projection 6 can merge flush with the fan blade 3, thereby achieving in particular improved aerodynamic behavior as well as a reduction of notch stresses.

[0035] Due to the delicate design of the projections 6 and the forces occurring during the operation of the fan wheel 1, the projections 6 can be made of a different material than the fan blade 3. For example, it is conceivable that the fan blade 3 is made of plastic and the projections 6 of metal. The projections 6 and the recesses 7 of the contour line 5 can be part of an inlay 13, in particular a metallic inlay, which is connected to the fan blade 3, which is made of plastic. The connection of the inlay 13 to the fan blade 3 can, for example, be made in a plastic injection mold, so that in this case the fan blade 3 and the inlay 13 are formed as a 2K plastic injection molded part.This not only allows for simpler manufacturing and increased strength of the inlay 13 with its attached projections 6, but also ensures a reliable and strong bond with the plastic of the fan blade 3. Generally, the entire fan wheel 1, with the exception of the inlays 13, can be manufactured as a single-piece injection-molded plastic part. Alternatively, it is also conceivable that the projections 6 with the recesses 7, as well as the fan blades 3, the hub 11, and the ring 12, are manufactured as a single-piece injection-molded plastic part. In this case, the entire fan wheel 1 is made of one and the same material, in particular plastic. A metal construction for the entire fan wheel 1 is also theoretically possible.

[0036] According to the invention, the contour line 5 is arranged at the leading edge 4 of the blade, and it is conceivable that such a contour line 5 could also be arranged at the trailing edge 14 of the blade. This allows for a further increase in the efficiency of the fan wheel 1 without having to accept an increased noise emission.

[0037] Furthermore, two directly adjacent projections 6 can be connected to each other, in particular via a connection not shown, which is in particular raised from a plane of the fan blade 3.

[0038] With the fan wheel 1 and the fan 2 according to the invention, a significant increase in efficiency can be achieved without having to accept increased noise emissions, which is particularly advantageous when used in noise-sensitive motor vehicles, especially electric vehicles. Furthermore, the fan wheel 1 according to the invention can be manufactured simply and cost-effectively. Reference symbol list 1 fan wheel 2 fans 3 fan blades 4 Leaf leading edge 5 Contour line 6 lead 7 Exclusion 8 Direction of rotation 9 trough 10 wave crest 11 Hub 12 Ring 13 Inlay 14 Leaf trailing edge QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 11035233 B2

[0002] WO 2013 / 180296 A1

[0003]

Claims

[1] Fan wheel (1) for a fan (2) with at least two fan blades (3) which have a wave- or tooth-like contour line (5) with projections (6) and recesses (7) on a respective blade leading edge (4), characterized by , that a ratio of a height A of the projections (6) to a wavelength W from one wave trough (9) to another wave trough (9) is defined as follows A / W≥1. [2] Fan wheel (1) according to claim 1, characterized by that the ratio is defined as follows A / W≥1.5, especially A / W≥2.

0. [3] Fan wheel (1) according to claim 1 or 2, characterized by , that the projections (6) are formed as round and / or angular wave crests (10) or as jagged edges. [4] Fan wheel (1) according to one of the preceding claims, characterized by, that the height A corresponds to at least 10% of a flow-over length BL, preferably at least 15% of a flow-over length BL, particularly preferably at least 20% of a flow-over length BL, of the fan blade (3). [5] Fan wheel (1) according to one of the preceding claims, characterized by , that the contour line (5) extends only to approximately 70%, preferably only to approximately 50%, of a radial length L of the fan blade (3). [6] Fan wheel (1) according to one of the preceding claims, characterized by that the contour line (5) begins at a hub (11), or that the contour line (5) begins at a distance from a hub (11). [7] Fan wheel (1) according to one of the preceding claims, characterized by , that at least one projection (6) is inclined in the circumferential direction relative to the fan blade (3). [8] Fan wheel (1) according to one of the preceding claims, characterized by , that at least one projection (6) has a greater thickness than the rest of the fan blade (3). [9] Fan wheel (1) according to any one of the preceding claims, characterized by , that at least one projection (6) of greater thickness merges flush into the fan blade (3). [10] Fan wheel (1) according to any one of the preceding claims, characterized by that the projections (6) are made of a different material than the fan blade (3). [11] Fan wheel (1) according to any one of the preceding claims, characterized by , that the fan blade (3) and the projections (6) are designed as a 2K plastic injection molded part. [12] Fan wheel (1) according to any one of the preceding claims, characterized by , that the fan blade (3) also has a wave- or jagged contour line (5) with protrusions (6) and recesses (7) on its trailing edge (14). [13] Fan (2), in particular for an air conditioning unit of an electric vehicle, with a fan wheel (1) according to one of the preceding claims.

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