Patent Application
20250198422
The embodiments described herein relate generally to axial fans, and more particularly, to an axial fan assembly including an axial fan comprising one or more blades and an intermediate shroud positioned proximate to a blade tip of the one or more blades.
At least some known axial fan assemblies include an axial fan with one or more blades designed to improve performance of the axial fan assembly. For example, the one or more blades may be designed to have a minimum blade thickness and/or to have complex curves to facilitate improved performance of the axial fan. However, blades that have a minimized thickness and/or have complex curves may be more prone to blade flexure, and/or blade tip fluttering, due to the significant size of the blades and the vibration that results from operation of the axial fan assembly.
Therefore, there is a need for an axial fan assembly that includes an axial fan with one or more blades and an intermediate shroud proximate to a blade tip of the one or more blades to facilitate damping vibration, reducing friction, and improving airflow.
In one aspect, an axial fan assembly is disclosed. The axial fan assembly includes an axial fan including a hub and one or more blades extending radially from a center point of the hub about which the axial fan rotates relative to an axis of rotation, each of the one or more blades extending a blade length out to a free edge defining an outermost edge of the one or more blades. The axial fan assembly also includes an intermediate shroud arranged radially outwards of the hub and radially inwards of the free edge of the one or more blades, wherein the intermediate shroud is positioned proximate the free edge of the one or more blades to increase stability of the one or more blades.
In another aspect, a method of using an axial fan assembly is disclosed. The method includes providing an axial fan including a hub and one or more blades extending radially from a center point of the hub about which the axial fan rotates relative to an axis of rotation, each of the one or more blades extending a blade length out to a free edge defining an outermost edge of the one or more blades. The method also includes arranging an intermediate shroud radially outwards of the hub and radially inwards of the free edge of the one or more blades, wherein the intermediate shroud is positioned proximate the free edge of the one or more blades, and rotating the axial fan, wherein the intermediate shroud increases stability of the one or more blades.
An axial fan assembly including an axial fan with one or more blades and an intermediate shroud proximate to a blade tip of the one or more blades is provided according to various embodiments of the present disclosure.
Each of the one or more blades 104 includes a free edge 114 defining an outermost edge of the blade 104 as measured from the center 112 of the hub 102, with a blade tip 115 defined along the free edge 114 defining an outermost end of the blade 104 as measured from the center 112 of the hub 102. Additionally, each of the one or more blades 104 includes a coupled end 116 joined to the sidewall 111 of the hub 102. In some embodiments, the sidewall 111 may extend substantially parallel to the axis of rotation 110. In other embodiments, the sidewall 111 may extend at an angle from the axis of rotation 110. The shape of the one or more blades 104 may be any suitable shape that enables the axial fan assembly 100 to function as described herein. Additionally, the shape of the free edge 114 of the one or more blades 104 may be any suitable shape that enables the axial fan assembly 100 to function as described herein.
The one or more blades 104 extend a blade length 118, measured radially from the sidewall 111 of the hub 102 (shown in
The intermediate shroud 120 may be a distance 126 measured between the intermediate shroud 120 and the sidewall 111 of the hub 102. The distance 126 between the intermediate shroud 120 and the sidewall 111 may be in a range of from about 60% of the distance from the sidewall 111 to the blade tip 115 to about 90% of the distance from the sidewall 111 to the blade tip 115.
Additionally, the intermediate shroud 120 may be located proximate blade tip 115. The blade tip 115 and the intermediate shroud 120 may be separated by a distance 128, from the blade tip 115 of the one or more blades 104. The distance 128 between the intermediate shroud 120 and the blade tip 115 may be in a range of from about 10% of the distance from the sidewall 111 to the blade tip 115 to about 40% of the distance from the sidewall 111 to the blade tip 115.
The intermediate shroud 120 being positioned proximate the free edge 114, and/or the blade tip 115, of the one or more blades 104, such as with the distance 128 between the intermediate shroud 120 and the blade tip 115, may facilitate improved efficiency and/or production of the axial fan assembly 100. For example, the intermediate shroud 120 may increase the stability of the one or more blades 104 by adding structural support along the blade length 118 of the blades 104. Thus, as a result of the increased stability of the blades 104, the intermediate shroud 120 may facilitate an increase in the flow rate achieved by the operation of the axial fan assembly 100 and/or an increase in the smoothness of the airflow produced by the axial fan assembly 100.
The intermediate shroud 220 has a lateral dimension 221 measured between a first shroud end 122 and a second shroud end 124. The lateral dimension 221 may be such that the intermediate shroud 220 extends through a leading edge and a trailing edge of the blade 104. For example, the lateral dimension 221 may extend up to 0.5 inches (0.0127 meters) beyond the leading edge of the blade 104. Additionally, for example, the lateral dimension 221 may extend up to 1.5 inches (0.0381 meters) beyond the trailing edge of the blade 104.
The axial fan assembly 200 may be used in conjunction with a plurality of vanes 230 downstream of the one or more blades 104. Each of the plurality of vanes 230 includes a vane leading edge 232 (shown in
The intermediate shroud 320 has a circumferential sinusoidal shape including one or more waves 340. The varying shape of the waves 340 is such that the radial offset of the intermediate shroud 320 along the hub 102 is not continuous. That is, each wave 340 includes a wave start 342 and a wave end 344, with the radial offset along the hub 102 of each of the waves 340 varying between the wave start 342 and the wave end 344. The radial offset decreases from the wave start 342 to a wave trough 345, increases from the wave trough 345 to a wave crest 346, and decreases from the wave crest 346 to the wave end 344. A wave height 347 as measured between the radial offset along the hub 102 at the wave trough 345 (circle A shown in
The sinusoidal shape of the intermediate shroud 320 as formed by the one or more waves 340 facilitates reduced sound from the axial fan assembly 300, such as harmonic tone and/or blade pass tone. In some embodiments, as illustrated in
The intermediate shroud 320 may include one or more balancing features to facilitate improved balance of the axial fan assembly 300. For example, the intermediate shroud may include one or more slots 352 in the second shroud end 324. In some embodiments, the number of slots 352 may be equal to the number of blades 104. In other embodiments, the number of slots 352 may be a multiple of the number of blades 104. Material may be deposited into the one or more slots 352 to balance the axial fan assembly 300 to facilitate reduced impact to the airstream and airflow proximate the blades 104, as compared to adding material to one or more edges of the blades 104. Additionally, less material may be required to be added to balance the axial fan assembly 300 when added to the intermediate shroud 320, as compared to closer to the center mass point of the axial fan assembly 300. Although the slots 352 are illustrated as part of the axial fan assembly 300, the slots 352 may be added to the intermediate shroud of the axial fan assembly 100 (e.g., the intermediate shroud 120) and/or the axial fan assembly 200 (e.g., the intermediate shroud 220).
Additionally, for example, the intermediate shroud 320 may include one or more bosses 354 in the second shroud end 324. In some embodiments, the number of bosses 354 may be equal to the number of blades 104. In other embodiments, the number of bosses 354 may be a multiple of the number of blades 104. The bosses 354 may provide an area for material removal, such as by drilling, to reduce the mass in a certain area to balance the axial fan assembly 300. Less material may be required to be removed to balance the axial fan assembly 300 when removed from the intermediate shroud 320, as compared to closer to the center mass point of the axial fan assembly 300. Although the bosses 354 are illustrated as part of the axial fan assembly 300, the bosses 354 may be included in the intermediate shroud of the axial fan assembly 100 (e.g., the intermediate shroud 120) and/or the axial fan assembly 200 (e.g., the intermediate shroud 220).
Further, for example, material may be added to and/or removed from the intermediate shroud 320 during the molding/casting process. In some embodiments, the intermediate shroud 320 may be formed using injection molding, including adjustable cores in the mold to adjust the amount of material injected into specific areas to facilitate improved balance of the axial fan assembly 300. Material may be added or removed during the molding/casting process from the intermediate shroud of the axial fan assembly 100 (e.g., the intermediate shroud 120) and/or the axial fan assembly 200 (e.g., the intermediate shroud 220).
A technical effect of the system described herein includes at least one of: (a) improved stability of one or more blades of an axial fan; (b) increased flow rate achieved by operation of the axial fan; (c) increased smoothness of airflow produced by the axial fan; (d) decreased sound produced by the axial fan assembly; (e) improved balance of the axial fan assembly; (f) reduced blade flutter of the axial fan; and (g) increased duration of fatigue life of the axial fan assembly.
In the foregoing specification and the claims that follow, a number of terms are referenced that have the following meanings.
As used herein, an element or step recited in the singular and preceded with the word “a” or “an” should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. Furthermore, references to “example implementation” or “one implementation” of the present disclosure are not intended to be interpreted as excluding the existence of additional implementations that also incorporate the recited features.
“Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here, and throughout the specification and claims, range limitations may be combined or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.
Disjunctive language such as the phrase “at least one of X, Y, or Z,” unless specifically stated otherwise, is generally understood within the context as used to state that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present. Additionally, conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, should also be understood to mean X, Y, Z, or any combination thereof, including “X, Y, and/or Z.”
The systems and methods described herein are not limited to the specific embodiments described herein, but rather, components of the systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein.
Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any layers or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
