KR20070083496A - Fan blades and modifications - Google Patents

Abstract

A winglet includes a vertical member and a mounting member. The mounting member is configured to facilitate the mounting of the winglet to the tip of a fan blade. The vertical member is configured to extend perpendicularly relative the tip of a fan blade. Adding winglets to fan blades may improve the aerodynamics of the fan blades, and thereby increase efficiencies of a fan.

Description

Fan blades and their variants {FAN BLADES AND MODIFICATIONS}

The present invention relates to fan blades and fan blade retrofits, and more particularly to airfoils suitable for use in fan blades and winglets suitable for use in fan blades.

Persons working on large structures or manufacturing facilities, such as warehouses, may be exposed to uncomfortable and dangerous work environments. The situation may also apply equally to farms, such as in structures filled with livestock. On hot days, the internal air temperature may reach a temperature at which a person or animal cannot maintain a normal desirable body temperature. In areas with unpleasant or unsafe temperatures, it would be desirable to install a mechanism to create or improve airflow within the area. Such airflow causes, in part, the temperature of the zone to be lowered.

In addition, any active action that occurs in the environment, such as the operation of welding or internal combustion engines, can produce airborne contaminants that can be harmful to exposure to them. The impact of airborne contaminants may be magnified if airflow in the zone is not ideal. In such or similar environments, it would be desirable to have a mechanism capable of generating or improving airflow within the zone. Such airflow can partially reduce the deleterious effects of contaminants such as dilution and / or removal of contaminants.

In certain structures and environments, heat may collect and remain near the ceiling of the structure, causing heat rise. This fact draws attention to the fact that it relatively cools the area near the bottom of the structure. Those skilled in the art will immediately recognize the disadvantages that may be raised by having such or other unbalanced air / temperature distributions. In such or similar situations it would be desirable to install a mechanism that could be operable to create or improve airflow within the zone. The air flow may in part result in a more ideal induction and non-laminar arrangement of the air / temperature distribution.

It is also advantageously possible to allow the fan to reduce energy consumption. Reduction of energy consumption can be achieved by having a fan that operates efficiently (eg requires little power to drive the fan relative to other fans). In addition, the reduction in energy consumption is brought about by having a fan that improves the air distribution, thereby reducing the heating or cooling costs associated with other devices.

Through the accompanying drawings, which form a part of this specification and describe, several examples of the invention are described for purposes of basic principles and description of the invention, and therefore, the described examples are for purposes of illustration only and are not intended to limit the invention. It should be understood as being described. In addition, in the drawings, like reference numerals have been assigned like reference numerals so as to refer to like elements.

1 is a plan view of a hub for mounting a fan blade;

2 is a cross-sectional view of an example fan blade airfoil.

3 is a cross-sectional view of another example fan blade airfoil.

4 is a graph showing two ellipses.

FIG. 5 illustrates a portion of the graph of FIG. 4. FIG.

6 is a side view of an example winglet fan blade modified.

Figure 7 is a cross sectional view of the winglet of Figure 6;

8 is a top view of the winglet of FIG.

Figure 9 is an end view of the fan blade of Figure 2 with the winglet of Figure 6 adapted.

10 is an exploded perspective view of the winglet-blade assembly of FIG.

Hereinafter, the present invention will be described with reference to the accompanying drawings, in which like elements indicate like elements throughout. 1 shows an example fan hub 10 used to provide a fan with fan blades 30 or 50. In an embodiment, the fan hub 10 has a plurality of hub mounting members 12 on which fan blades 30 or 50 are mounted. In one embodiment, fan hub 10 is coupled to a drive mechanism that rotates fan hub 10 at an optional or predetermined speed. Thus, a suitable hub assembly may comprise the hub 10 and a drive mechanism coupled to the hub 10. Of course, the hub assembly may have various other elements with other hubs, and the fan hub 10 may be driven by any suitable means. In addition, the fan hub 10 may have any suitable number of hub mounting members 12.

As shown in Figs. 1 to 3, each hub mounting member 12 has an upper surface 14 and a lower surface 16 which terminate at the leading edge 18 and trailing edge 20 side. Has In addition, each hub mounting member 12 has an opening 22 formed through the upper surface 14 and through the lower surface 16. In an embodiment, the aperture 22 is sized to receive the fastener 26. Each hub mounting member 12 has a structure for accommodating the fan blades 30 or 50. Those skilled in the art will appreciate that the hub mounting member 12 may be provided in a variety of optional configurations.

In one embodiment, fan blades 30 or 50 are mounted to the hub assembly disclosed in US Pat. No. 6,244,821. Of course, fan blades 30 or 50 may be mounted to any other hub and / or hub assembly. In operation of a suitable hub assembly, the hub 10 rotates at any suitable angular speed. As an example, the angular velocity is in the range of approximately 7 to 108 rpm in any region.

FIG. 2 is a cross-sectional view of a fan blade 30, for example with a curly form of trailing edge 38 mounted to the hub 10. The cross section is cut along the cross section located in the center of the fan blade 30 when viewed toward the hub 10. The fan blade 30 has an upper face 32 and a lower face 34, each face ending at an anterior edge 36 and an anterior edge 38. As shown, the anterior chamber 38 consists of an inclination of approximately 45 ° with respect to the upper surface 32 portion near the rear anterior 38 and the lower surface 34 portion near the rear anterior 38. Of course, the trailing edge 38 may have any other suitable slope, such as, for example, 0 °, in the range containing a single flat surface. Other suitable back 38 structures will be readily understood by those skilled in the art.

In the given example, the fan blades 30 are approximately hollow. A plurality of ribs or bosses 40 are inserted into the fan blades 30. As shown, when the hub mounting member 12 is inserted into the fan blades 30, the ribs or bosses 40 are at the top surface 14, the bottom surface 16, the leading edge 18, and the hub mounting member ( It is located in contact with the trailing edge 20 of 12). Thus, the boss 40 provides an appropriate fit between the fan blade 30 and the hub mounting member 12. Other suitable structures for the fan blades 30 that have a structure that affects the correlation between the fan blades 30 and the hub mounting member 12 as a non-limiting substrate may be readily understood by those skilled in the art. will be.

As used herein, terms such as "chord", "cord length", "maximum thickness", "maximum camber", "angle of attack" and the like refer to airplane wings or other airfoil design technologies. It is described in the same meaning as described in the terms used in. In one embodiment, fan blades 30 have a cord length of approximately 6.44 inches. The fan blade 30 has a maximum thickness of approximately 16.2% of the cord and a maximum camber of approximately 12.7% of the cord. The radius of lead 36 is approximately 3.9% of the cord. The radius of the trailing edge 38 quadrant of the lower face 34 is approximately 6.8% of the cord. In another embodiment, fan blade 30 has a cord of approximately 7 inches. In another embodiment, fan blade 30 has a cord of approximately 6.6875 inches. Of course, any other suitable dimension and / or property may be used.

For example, fan blade 30 exhibits lift to drag ratios in the range of approximately 39.8 with a Reynolds number of approximately 120,000 and approximately 93.3 with a Reynolds number of approximately 250,000. Of course, other lift ratios may be obtained from the fan blades 30.

In one embodiment, fan blade 30 exhibits drag coefficients ranging from approximately 0.027 with a Reynolds number of approximately 75,000 to approximately 0.127 with a Reynolds number of approximately 112,500. Of course, other drag coefficients can be obtained from the fan blades 30.

In one embodiment, with the Reynolds number approximately 200,000, the fan blades 30 operate in air such that the speed ratio is approximately 1.6 to the bottom surface 34 at the trailing edge 38 of the fan blades 30. Other speed ratios can be obtained from the fan blades 30.

In one embodiment, fan blades 30 provide non-stall aerodynamics for the angle of attack between approximately -1 ° and 7 ° with a Reynolds number of approximately 112,000 and approximately-with a Reynolds number of approximately 250,000. Provides non-stall aerodynamics for the angle of attack between 2 ° and 10 °. Of course, these values are shown by way of example only.

FIG. 3 shows another example of a fan blade 50 having an approximately elliptical top surface 52 and a bottom surface 54 each leading to an anterior 56 and anterior 58 mounted on a hub 10. It is a figure shown by the cross section. The cross section is cut along the transverse plane located at the center of the fan blade 50 as viewed toward the hub 10. In this example, the fan blade 50 is hollow. A plurality of bosses 60 are installed inside the fan blade 50. As shown, when the hub mounting member 12 is inserted into the fan blade 50, the boss 60 is the upper surface 14, the lower surface 16, the leading edge 18 of the hub mounting member 12, And it is placed in contact with the trailing edge (20). Thus, the boss 60 provides a snug fit between the fan blade 50 and the hub mounting member 12. As a non-limiting substrate, other structures of the fan blade 50 made of a structure that affects the relationship between the fan blade 50 and the hub mounting member 12 can be easily foreseen by those skilled in the art. will be.

As shown, the fan blade 50 has a smaller radius of curvature towards the leading edge 56 as compared to the larger radius of curvature towards the trailing edge 58. The curvature of the fan blade 50 may be at least partially obtained by forming two ellipses using the following equation. One skilled in the art will appreciate that a first ellipse whose origin is the intersection of the x and y axes of the Cartesian coordinates can be made by the following equation.

[1] x = a (COS (t))

[2] y = b (SIN (t))

Where a = length of the first radius, b = length of the second radius, and t = radial rotation angle (eg, radians) relative to the origin.

Thus, the first ellipse can be generated using the above equation. Similarly, the coordinate set for the first ellipse can be obtained by using the formulas [1] and [2]. For example, the first ellipse 200 is illustrated in the graph of FIG. 4, where a = 3 and b = 2.

The coordinates for the second ellipse are obtained using the following equation.

[3] x ₂ = x (COS (θ))-y (SIN (θ)),

[4] y ₂ = y (COS (θ))-x (SIN (θ))

Where x ₂ is the second "x" coordinate after the in-situ rotation of the first ellipse in θ radians with respect to the origin, and y ₂ is the second "y after the rotation of the first ellipse in θ radians with respect to the origin. "Coordinates.

Thus, the dimensions of the second ellipse depend on the dimensions of the first ellipse. An example second ellipse 300 is illustrated in the graph shown in Figure 4, where θ = 0.525 radians. Here, it can be seen that the first and second ellipses are represented by coordinates according to equations [1] to [4], and the two ellipses cross each other (elliptical intersection) at four points. 4 illustrates four ellipse intersections 400 between the first ellipse 200 and the second ellipse 300.

The curvature of the upper surface 52 and the lower surface 54 is based at least in part on the curvatures of the first and second ellipses between two consecutive elliptic intersections. FIG. 5 showing ellipses 200 and 300 between successive ellipse intersections 400 shows an example of a section of the first ellipse 200 and the second ellipse 300. Accordingly, equations [1] to [4] are used to generate surface coordinates for at least the lower surface 54 and the upper surface 52 of the fan blade 50.

It will be appreciated that the cord length-to-thickness ratio of the fan blade 50 may vary with the amount of rotation θ in relation to the two ellipses.

Of course, the fan blade 50 portion may deviate from the curvature of the first and second ellipses. By way of example only, the leading edge 56 can be modified to have a generally circular curvature. Those skilled in the art will appreciate that other deviations can be made.

In one embodiment, the fan blade 50 is obtained using equations [1] to [4], where a = 3 units, b = 2 units, and θ = 0.525 radians. In this embodiment, the fan blade 50 is installed with a circular leading edge 56 having a diameter of 3.5% of the cord length. The curvature of the leading edge 56 is a tangential to the curvature of the upper surface 52 and the lower surface 54.

In one embodiment, fan blade 50 has a cord length of approximately 7.67 inches. In another embodiment, the fan blades have a cord length of approximately 7.687 inches. Of course, fan blades 50 may have other suitable cord lengths.

In this example, the radius of leading 56 is approximately 3.5% of the cord. The maximum thickness of the fan blade 50 is approximately 14.2% of the cord. The maximum camber of the fan blade 50 is approximately 15.6% of the cord. Of course, any other suitable dimensions and / or ratios may be used.

In this example, a fan with 10 fan blades 50 mounted at an angle of attack of 10 ° and having a 24 foot diameter is displaced at approximately 87,302 cubic feet per minute (cfm) and, when rotating at approximately 7 rpm, approximately Generates 5.2 lb thrust. When rotating at approximately 14 rpm, the fan displaces at approximately 124,174 cfm, producing approximately 10.52 lb of thrust. When rotating at approximately 42 rpm, the fan displaces at approximately 322,613 cfm, producing approximately 71.01 lb of thrust. Other thrust and / or displacement volumes are obtained by the fan with fan blades 50.

By way of example only, for example, a fan blade 50 having an angle of attack of approximately 10 ° may have a drag ratio in the range of between about 39 and about 60 with a Reynolds number of about 250,000 with a Reynolds number of about 120,000. Indicates. Other drag ratios may be obtained from the fan blades 50.

In one embodiment, fan blade 50 provides non-stall aerodynamics for the angle of attack between approximately 1 ° to 11 ° at a Reynolds number of approximately 112,000 and approximately 0 ° at a position of approximately 200,000. Provide non-stall aerodynamics for the angle of attack between 13 ° and 13 °, and non-stall aerodynamics for the angle of attack between approximately 1 ° and 13 ° where the Reynolds number is approximately 250,000. Of course, these values are shown by way of example only.

In one example, a fan 14 feet in diameter and containing 10 fan blades 50 rotates at approximately 25 rpm. The fan has a torque of approximately 78.80 inch-pounds (in. Lbs.) And a flow rate of approximately 34,169 cfm and operates at approximately 54 watts. Thus, the fan has an efficiency of approximately 632.76 cfm / watt.

In another example, a fan 14 feet in diameter and containing 10 fan blades 50 rotates at approximately 37.5 rpm. The fan has a torque of approximately 187.53 inch-pounds (in. Lbs.) And a flow rate of approximately 62,421 cfm and operates at approximately 82 watts. Thus, the fan has an efficiency of approximately 761.23 cfm / watt.

In another example, a fan 14 feet in diameter and containing 10 fan blades 50 rotates at approximately 50 rpm. The fan has a torque of approximately 376.59 inch-pounds (in. Lbs.) And a flow rate of approximately 96,816 cfm and operates at approximately 263 watts. Thus, the fan has an efficiency of approximately 368.12 cfm / watt.

The following applies only to the fan blades 30 or any fan blades with fan blades 50 as described, for example.

In one embodiment, each fan blade 20 or 50 comprises homogeneous continuum material. For example, fan blades 30 and 50 are constructed of extruded aluminum. However, it will be appreciated that fan blades 30 and / or 50 may be constructed of any other suitable material (s) containing any metal and / or plastic, as a non-limiting substrate. In addition, the fan blades 30 and / or 50 may be manufactured by any suitable manufacturing method including, but not limited to, stamping, bending, welding and / or molding. Those skilled in the art will also be able to anticipate other suitable manufacturing methods and materials.

As the fan blades 30 or 50 are mounted to the hub 10, the hub mounting member 12 extends toward the fan blades 30 or 50, for example, approximately six inches. Alternatively, the hub mounting member 12 extends toward the fan blades 30 or 50 at any suitable length. It will also be appreciated that, as would be expected, it may have a mounting member 12 installed outside the fan blades 30 or 50 in addition to the inside. Alternatively, the mounting member 12 may be installed on both sides, which are partly inner and partly outer fan blades 30 or 50.

The fan blades 30 or 50 also have one or more open holes formed in the structure in which the open holes 22 are aligned with the hub mounting member 12. In this embodiment, when the open holes in the fan blades 30 or 50 are installed in alignment with the open holes 22 in the hub mounting member 12, the fasteners 26 are inserted through the open holes to provide fan blades ( 30 or 50) to the hub mounting member 12. In one embodiment, fastener 26 is a bolt. Those skilled in the art will appreciate that other suitable for fastener (s) 26 may be provided by way of example and not by way of limitation. Thus, it will be understood that the opening 22 is selectively selected.

The fan blades 30 or 50 may be any length of approximately 4 to 14 feet in length. Optionally, fan blades 30 or 50 may be of any other suitable length. In one embodiment, fan blades 30 or 50 and hub 10 are sized such that a fan containing fan blades 30 or 50 and hub 10 has a diameter of approximately 24 feet. In another embodiment, fan blades 30 or 50 and hub 10 are sized such that a fan containing fan blades 30 or 50 and hub 10 has a diameter of approximately 14 feet. Those skilled in the art will appreciate that other suitable dimensions can be achieved.

Those skilled in the art will appreciate that not all cross sections along the length of the fan blades 30 or 50 need to be made identical. That is, the structure of the fan blades 30 or 50 need not be made constant along the entire length of the fan blades 30 or 50. By way of example only, portions of the “hub mounting end” of the fan blades 30 or 50 (eg, the ends of the fan blades 30 or 50 mounted to the hub 10) may be removed. have. In one example, an inclined cutout may be made in front of the fan blades 50 to accommodate the other blades 50 on the hub 10.

Optionally, fan blades 30 or 50 may be formed or constructed such that a portion or other portion of the hub mounting end is omitted. By not having the above-described parts (not considered removed or not having such parts), it can be expected that the problems with fan blades 30 or 50 which interfere with each other at the hub 10 can be alleviated. will be. The obstacle is caused by various factors including the cord length of the fan blades 30 or 50 as non-limiting substrates. Of course, in addition to the failure, the factor may affect the removal by part of the fan blades 30 or 50 or the lack by other means. The lacking portion may comprise a portion of the anterior segment 36 or 56, a portion of the trailing segment 38 or 58, or both portions.

Optionally, the diameter of the hub can be increased (eg, not increasing the number of hub mounting members 12) to lead to failure of the fan blades 30 or 50 in the hub 10. Alternatively, the cord of the fan blades 30 or 50 can be reduced. Those skilled in the art will appreciate various other changes and modifications of the hub 10 and / or fan blades 30 or 50.

Those skilled in the art will appreciate that the fan blades 30 or 50 may have a zero or nonzero angle of attack. By way of example only, when mounted to the hub mounting member 12, the fan blades 30 or 50 may comprise, for example, between -2 ° and 10 °; Or an angle of attack in the range of approximately −1 ° to 7 °, including approximately 7 °, 8 °, 10 °, or 13 °. Of course, the fan blades 30 or 50 may have any suitable angle of attack. The fan blades 30 or 50 are generally linear along the length and the angle of attack is given to have the hub mounting member 12 of the desired angle of attack.

Optionally, the angle of attack of the hub mounting member 12 is zero, and the angle of attack for the fan blades 30 or 50 is given by a twist on the fan blades 30 or 50. That is, the fan blades 30 or 50 are generally linear along the length of which the hub mounting member 12 extends from the fan blades 30 or 50, and the twist is for the rest of the fan blades 30 or 50. It will be given to provide the angle of attack. The twist occurs above any suitable length of the fan blades 30 or 50 (eg, the entire remaining length of the fan blades 30 or 50 has a twisted portion; or of the fan blades 30 or 50). Almost all of the remainder is generally straight, the twisted part being short). Those skilled in the art will envisage other structures and methods suitable for providing an angle of attack for all or part of the fan blades 30. In addition, one of ordinary skill in the art would anticipate having all or any portion of fan blades 30 or 50 having one or more twisted portions suitable for any purpose.

Those skilled in the art will appreciate that fan blades (eg 30 or 50) can be modified in various ways. Modifications of the fan blades in various ways will vary the performance characteristics of the fans. In one modification of the embodiment shown, for example, in Figs. 6 to 10, the winglets 70 are provided. Winglets 70 will be described with respect to fan blades 30 or 50, but it will be appreciated that the winglets 70 can also be used with any other suitable fan blade.

The winglet 70 in this example has a vertical member 72. The vertical member 72 includes a flat inner surface 74 and a rounded outer surface 76. Those skilled in the art will appreciate that there are other suitable structures for the inner surface 74 and the outer surface 76. In this example, the perimeter of the vertical member 72 is defined by the lower edge 78, the upper edge 80, and the rear edge 82. Each edge 78, 80, 82 generally meets at each edge 84. Thus, in this example, vertical member 72 has three edges 84. As shown, each edge 84 is rounded. Thus, the expression "corner" used herein should not be understood as reminiscent of a sharp angle. That is, the corner does not need to be limited to a point or an area where a set of straight lines meet or intersect. Although the vertical member 72 is described as having three corners in this example, it will be understood that the vertical member 72 may have an appropriate number of corners 84.

Those skilled in the art will appreciate that the vertical member 72 can make other suitable modifications.

In addition, the winglet 70 of this example has a winglet mounting member 90, which is formed extending in a direction substantially perpendicular to the inner surface 74 of the vertical member 72. As shown in FIG. As shown, the winglet mounting member 90 has a structure similar to that of the hub mounting member 12. The winglet mounting member 90 has an upper surface 92 and a lower surface 94 finished at the front edge 96 and the rear edge 98, respectively. In addition, the winglet mounting member 90 has an open hole 100 formed through the upper surface 92 and the lower surface 94. In this example, each open hole 100 has a structure that is inserted into an end of a fan blade 30 or 50. Those skilled in the art will appreciate that the winglet mounting member 90 may be provided in a different configuration.

9 is a cross section of a fan blade 30 with a winglet 70 mounted to the fan blade. The cross section is cut along the transverse plane located in the center of the fan blade 30 when viewed toward the winglet 70 (eg, away from the hub 10). In this example, and as shown in Figs. 9 and 10, the winglet mounting member 90 has a structure fitted to the end of the fan blades 30 or 90. Similar to the hub mounting member 12, the winglet mounting member 90 is installed stably with respect to the boss 40 or 60 in the fan blades 30 or 50. In this example, the upper edge 80 of the winglet 70 extends above the top surface 32 or 52 of the fan blades 30 or 50 in addition to extending beyond the leading edge 36 or 56. Similarly, the lower edge 78 of the winglet 70 extends below the lower surface 34 or 54 of the fan blades 30 or 50. The rear edge 82 of the winglet 70 extends beyond the trailing edge 38 or 58 of the fan blades 30 or 50. Of course, the winglets 70 and fan blades 30 or 50 may have any other suitable size and / or structure.

The fan blades 30 or 50 have one or more open holes formed near the leading end of the fan blades 30 or 50 via the upper surface 32 or 52 and / or the lower surface 34 or 54, and the surface Is sized to accommodate the fastener 26 and to be aligned with the opening (s) 100 in the winglet mounting member 90 when the winglet mounting member 90 is inserted into the fan blades 30 or 50. Is done. Thus, the winglets 70 may be secured to the fan blades 30 or 50 by one or more fasteners 26. In one embodiment, fastener 26 is a bolt. In another embodiment, the fasteners 26 may be formed of a suitable pair of thin heads of mutually binding binding screws (e.g., "female" screws with threaded inner surfaces), such as screw posts, which are often used to bond large quantities of paper together. And " male " screws with threaded outer surfaces of mating structures. However, any other suitable fastener (s) included without limitation to adhesion may be used. Thus, it will be appreciated that the open hole 100 is optional.

It will also be appreciated that the winglet mounting member 90 need not be inserted into the end of the fan blades 30 or 50. That is, in other words, similar to the hub mounting member 12, the winglet mounting member 90 may be made to be installed outside the fan blades 30 or 50, rather than the inside. Optionally, the winglet mounting member 90 may be installed partially on the inside and partially on both sides of the outer fan blades 30 or 50. Those skilled in the art will appreciate that other structures may exist.

In an alternative embodiment, the winglets 70 have recesses formed in the inner surface 74 of the vertical member 72 instead of lacking the mounting member 90. In this embodiment, the tip of the fan blades 30 or 50 is inserted into the winglets 70 to attach the winglets 70 to the fan blades 30 or 50. In other embodiments, fan blades 30 or 50 are integrally formed with winglets 70. Thus, those skilled in the art will anticipate that there are various structures for installing the winglets 70 to the fan blades 30 or 50.

Although the vertical member 72 is shown as being generally perpendicular to the mounting member 90, it should be understood that the two members may be at any suitable angle to each other. Thus, by way of example only, the vertical member 72 can be tilted inward or outward when the winglet 70 is attached to the fan blades 30 or 50. Optionally, the vertical member 72 may contain more than one angle. That is, the vertical member 72 may have a structure in which the upper portion of the vertical member and the lower portion of the vertical member may be inclined inward when the winglets are attached to the fan blades 30 or 50, respectively. Other changes in the winglet 70 may be made by those skilled in the art, including non-limiting substrates, including angle changes.

Although the winglets 70 have been specifically described herein as modifications to the fan blades 30 or 50, it will be appreciated that the winglets 70 can be used to modify any other fan blade.

In one embodiment, the winglets 70 are formed of homogeneous molded plastic continuum. However, it will be appreciated that the winglets 70 may be made of various materials containing any suitable metal and / or plastic as a non-limiting substrate and may include a plurality of pieces. It is also to be understood that the winglets may be manufactured by any suitable method of manufacture.

It may also be expected that trailing vortices formed at or near the tip of the fan blades 30 or 50 will raise the lift near the tip of the fan blades 30 or 50. The winglets 70 obstruct radial airflow over the upper surface 32 or 52 and / or the lower surface 34 or 54 near the tip of the fan blades 30 or 50. This obstruction more normally forces air to flow from the leading edge 36 or 56 to the trailing edge 38 or 58, thereby providing a fan with fan blades 30 or 50 with winglets 70 at least at any arbitrary rotational speed. To improve the efficiency.

In one example, the winglets 70 are attached to the ends of fan blades 30 or 50 in a six foot diameter fan. With the addition of the winglets 70, the fan airflow rate is increased by 4.8% at 171 rpm.

In another example, the winglets 70 are attached to the ends of fan blades 30 or 50 in a fan having a 14 foot diameter. With the addition of the winglets 70, the fan airflow rate is increased by 4.4% at 75 rpm.

The next two tables show the efficiencies obtained by adding winglets 70 to a 14 foot diameter fan.

Table 1: Fans without winglets (70)

Speed (rpm) Max Power (watt) Average Power (watt) Torque (in.lbs) Flow rate (cfm) Efficiency (cfm / watt) 12.5 54 50 17.86 0 0 25 66 54 78.80 34,169 632.76 37.5 125 82 187.53 62,421 761.23 50 339 263 376.59 96,816 368.12 62.5 700 660 564.01 110,784 167.85 75 1170 1140 839.75 129,983 114.02

Table 2: Fans with Winglets (70)

Speed (rpm) Max Power (watt) Average Power (watt) Torque (in.lbs) Flow rate (cfm) Efficiency (cfm / watt) 12.5 50 42 18.56 26,815 638.45 25 58 43 18.39 46,547 1,082.49 37.5 68 49 186.00 61,661 1,258.39 50 241 198 354.61 87,552 442.18 62.5 591 528 582.78 120,859 228.90 75 980 950 847.41 136,560 143.75

Of course, other values may be realized through the use of winglets 70. In addition, as can be understood by those skilled in the art, as a non-limiting substrate, it is possible to realize a proper change of the winglet having a modified winglet structure.

In summary, the present invention can take a number of benefits using the concept of the present invention. The description of one or more embodiments of the invention is described for purposes of illustration, and the invention is not limited to the embodiments described above. It is intended that the present invention cover various modifications and adaptations that may be made without departing from the spirit of the appended claims based on the above description.

Claims (25)

The winglets for the fan blades are: (a) a vertical member; (b) a mounting member; At least a portion of the mounting member is generally perpendicular to at least a portion of the vertical member, the mounting member is configured to be mounted to the fan blade first end and the fan blade is mounted to the fan hub at the second end of the fan blade. And wherein the second end faces the first end. 2. The winglet of claim 1, wherein the vertical member comprises a rounded outer surface. 3. The winglet of claim 2, wherein the vertical member further comprises an approximately flat inner surface. 2. The winglet of claim 1, wherein the vertical member has a perimeter defined by a lower edge, an upper edge, and a rear edge. 5. The winglet of claim 4, wherein each of said edges substantially meets at each corner. 6. The winglet of claim 5, wherein each of the corners is generally rounded. The wing blade for a fan blade according to claim 1, wherein at least a part of the mounting member is formed inside the fan blade first end. 2. The winglet of claim 1, wherein the vertical member is configured to block radial airflow over at least a portion of the fan blade in the vicinity of the fan blade first end. 2. The winglet of claim 1, wherein the mounting member comprises an inner surface and at least a portion of the inner surface is at a non-vertical angle relative to the mounting member. The wing blade of claim 1, wherein the mounting member is configured to be fixed to the first end of the fan blade by one or more fasteners. The vertical member of claim 1, wherein the vertical member has an upper edge, the mounting member has an anterior edge, and when mounted to the first end of the fan blade having the anterior edge, the vertical member is moved up to one point from the front edge of the vertical member to the upper edge of the vertical member. A winglet for fan blades, characterized in that the distance is greater than the distance from the front of the mounting member to the front of the fan blade at the first end. 2. The vertical member of claim 1, wherein the vertical member has a rear edge, the mounting member has a rear edge, and when mounted to the first end of the fan blade having the rear edge, the vertical member has a rear edge of the vertical member up to one point. A wing blade for a fan blade, characterized in that the distance is greater than the distance from behind the mounting member to behind the fan blade at the first end. The vertical member of claim 1, wherein the vertical member has a lower edge, and the mounting member has a lower surface, and when mounted on the first end of the fan blade having the lower surface, the vertical member has a lower edge of the vertical member. And the distance to the point is greater than the distance from the bottom surface of the mounting member to the bottom surface of the fan blade at the first end of the fan blade. 2. The mounting member of claim 1, wherein the vertical member has an upper edge, and the mounting member has an upper surface, and when mounted on the first end of the fan blade having the upper surface, the mounting member has an upper edge. And the distance to the point is greater than the distance to any point on the top surface of the fan blade at the first end of the fan blade at the mounting member top surface. In a retrofit kit for a fan blade, the kit is: (a) a vertical member; (b) a mounting member; (c) at least one fastener having a structure for fixing the mounting member to the first end; (b ') The mounting member is generally perpendicular to at least a portion of the vertical member, the mounting member is configured to be mounted to the fan blade first end, the fan blade is a fan hub at the second end of the fan blade And a second end facing the first end, wherein the second end is facing the first end. The fan is: (a) a hub operating with the rotor; (b) a plurality of fan blades, each fan blade having a first end and a second end; (c) a winglet mounted to the second end of each fan blade; (b ') A fan, wherein each fan blade is mounted to the hub at its first end. 17. The fan of claim 16, wherein each winglet comprises a vertical member and a mounting member. 18. The fan of claim 17, wherein the mounting member extends substantially vertically from the vertical member. 18. The fan of claim 17, wherein at least a portion of each mounting member is configured to be installed at the second end of each fan blade. 17. The fan of claim 16, wherein a distance between the first and second ends of each fan blade is at least approximately 4 feet. A method of retrofitting a fan blade, the method comprising securing a winglet to the fan blade end; The winglet has a vertical member and a mounting member; At least a portion of the mounting member is generally perpendicular to at least a portion of the vertical member; The mounting member is a fan blade retrofit method, characterized in that consisting of a structure coupled to the fan blade end. In a fan blade structure mounted to a rotating fan hub, the fan blade comprises: (a) an upper surface having an approximately elliptical curvature; (b) a bottom surface having an approximately elliptical curvature; (c) the leading edge and each of the upper and lower edges terminates in the leading edge; (d) a fan blade comprising a trailing edge, wherein the upper and lower surfaces each terminate at the trailing edge. 23. The fan blade of claim 22, wherein the fan blade further includes a first radius of curvature near the front and a second radius of curvature near the rear, and the first radius of curvature is smaller than the second radius of curvature. . 23. The fan blade of claim 22, wherein the curvature of the upper surface is based on a first ellipse and the curvature of the lower surface is based on a second ellipse. 25. The fan blade of claim 24, wherein the curvature of the second ellipse is in accordance with the curvature of the second ellipse.

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