Claims:We claim:
1. A ceiling fan blade (101) for high air delivery in ceiling fan system (100), the ceiling fan blade (101) comprising:
a rotor end (101b) towards rotor of the ceiling fan (100), wherein the rotor end (101b) has a rib structure (101e);
a tip end (101a) at distal end of the ceiling fan blade (10);
wherein the ceiling fan blade (101) has an aerofoil shaped profile which is thicker at the rotor end (101b) tapering down to a thinner at the tip end (101a), for providing high lift and low drag, wherein the ceiling fan blade (101) has twist angle (301) in range of 19o to 11o along length of the ceiling fan blade, wherein the twist angle (501) decreases non-uniformly from the rotor end (101b) to the tip end (101a).
2. The ceiling fan blade (101) as claimed in claim 1, wherein the thickness at rotor end (101b) is in range of 7 to 9 mm, preferably 8mm.
3. The ceiling fan blade (101) as claimed in claim 1, wherein the thickness at tip end (101b) is in range of 1 to 3 mm, preferably 2mm.
4. The ceiling fan blade (101) as claimed in claim 1, wherein the ceiling fan blade (101) has lift angle about 10o.
5. The ceiling fan blade (101) as claimed in claim 1, wherein the ceiling fan blade (101) has section at AA, BB, CC, and DD from the rotor end (101b) to the tip end (101a) at equal distance of 115mm from each other, the section AA which is closer to the rotor end (101b) has twist angle of approximately 19o, the section BB has twist angle of approximately 14o, the section CC has twist angle of approximately 12o, and the section DD has twist angle of approximately 11o.
6. The ceiling fan blade (101) as claimed in claim 1, wherein length of ceiling fan blade (101) is approximately 645 mm.
7. The ceiling fan blade (101) as claimed in claim 1, wherein the ceiling fan blade (101) has a winglet at the tip end (101a).
8. The ceiling fan blade (101) as claimed in claim 1, wherein the ceiling fan blade (101) has curved width profile to reduce drag.
9. The ceiling fan blade (101) as claimed in claim 1, wherein the ceiling fan blade (101) is aerofoil compounded polymer blade.
10. The ceiling fan blade (101) as claimed in claim 1, wherein the ceiling fan blade (101) is Polyurethane (PU) painted.
Dated this 9th day of October 2017
, Description:AEROFOIL DESIGN BLADE FOR CEILING FAN
FIELD OF INVENTION:
[001] The present subject matter described herein, relates to ceiling fan, and, in particular, to blade of ceiling fan with aerofoil shaped profile having variable twist angle along length of the blade for higher air delivery.
BACKGROUND AND PRIOR ART:
[002] Generally, ceiling fans are powered by electric motors for circulating air. The ceiling fan has a motor within housing, i.e., hub mounted to a down rod that rotates a plurality of fan blades connected with the motor about the axis of the down rod. Their blades have traditionally been flat and oriented at an incline or pitch to present an angle of attack to the air mass in which they rotate. This causes air to be driven downwardly.
[003] When a fan blade that extends generally radially from its axis of rotation is rotated, its tip end travels in a far longer path of travel than does its root end for any given time. Thus, its tip end travels much faster than its root end. To balance the load of wind resistance along the blades, and the air flow generated by their movement, fan blades have been designed with an angle of attack that diminishes towards the tip.
[004] The ceiling fan or axial fan is suspended above the ground, the ceiling fan sucks air radially. This means that the air flow is not fully perpendicular to the fan blades. Also wind causes variations in the air flow direction relative to the fan blade. This variation in air flow direction relative to the fan blades causes a non optimal functioning of the fan. It is known to use twisted fan blades to optimize the aerodynamic angle of attack of the fan blade. However, due to wind and to other particular conditions that can create turbulence at the outboard edge of the blade, twisting of the fan blade does not provide an optimal solution for the outboard edge zone of a fan blade. These conditions could cause such an air flow direction relative to the tip of the fan blade, that stall can occur in the outboard edge zone resulting in lower performance, lower efficiency of the fan blade and causing extra noise.
[005] Existing conventional ceiling fans comes with metal blade with bend or curved shape which gives optimum air delivery as per the shape of blade. There are some plastic blades also available in ceiling fan with flat shape and uniform thickness that also gives similar air delivery. There is need to develop a ceiling fan which gives the maximum air delivery with less noise with very variable thickness as compared to the conventional ceiling fan.
OBJECTS OF THE INVENTION:
[006] The principal objective of the present invention is to provide an aerofoil shaped blade for ceiling fan.
[001] Another object of the present invention is to provide aerofoil shaped blades for higher air spread with low noise.
[002] Another object of the present invention is to provide higher air delivery in sweep of 1300mm.
[007] Another object of the present invention is to provide maximum air delivery about 300 CMM.
[008] Another object of the present invention is to provide aerofoil blade with variable thickness for increasing the air delivery.
[009] Yet another object of present invention is to provide an aerofoil shaped blade with optimized lift angle and twist angle for higher air delivery.
[0010] Yet another object of present invention is to develop an aerofoil shaped blade with curved profile and with length 645mm.
[0011] Yet another object of the present invention is to provide an aerofoil shaped blade with tapered profile where wider portion at rotor end tapering down to a thinner portion at tip end, for providing high lift and low drag.
[0012] Yet another object of the present invention is to provide an aerofoil shaped blade with a winglet at tip end to reduce vortex.
[0013] Yet another object of the present invention is to provide a simple and cost effective ceiling fan with aerofoil shaped blades for higher air delivery and loss noise.
SUMMARY OF THE INVENTION:
[0014] The present subject matter relates to a ceiling fan with aerofoil shaped blade for higher air delivery at fan sweep of 1300mm. The present aerofoil shaped blade has curved profile and variable thickness to provide higher air delivery and less noise. The aerofoil shaped blade has twist angle is in range of 19o to 11o which decreases non-uniformly from rotor end to tip end of the blade. Further, the aerofoil shaped blade has thickness at rotor end in range of 7 to 9mm and at tip end in the range of 1 to 3mm. The aerofoil shaped blade has lift angle of 10o with reference to horizontal axis of the blade. Due to the curved profile, aerofoil shaped profile, and variable thickness with non-uniform optimized twist angle provides higher air delivery at fan sweep of 1300mm.
[0015] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0017] Fig. 1 illustrates ceiling fan with aerofoil shaped blade, in accordance with an embodiment of the present subject matter;
[0018] Fig. 2 illustrates lift angle of the aerofoil shaped blade, in accordance with the present subject matter;
[0019] Fig. 3 illustrates twist angle of the aerofoil shaped blade, in accordance with an embodiment of the present subject matter;
[0020] Fig. 4 illustrates variable twist angle according to thickness and length of the aerofoil shaped blade, in accordance with an embodiment of the present subject matter;
[0021] Fig. 5 illustrates twist angle with various cross section of the aerofoil shaped blade as shown in the figure 4, in accordance with an embodiment of the present subject matter; and
[0022] Fig. 6 illustrates cover to be provided at hub end to hide ribs of the hub end of the aerofoil shaped blade, in accordance with an embodiment of the present subject matter.
[0023] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0024] The present subject matter relates to a ceiling fan with aerofoil shaped blade for higher air delivery at fan sweep of 1300mm. The present aerofoil shaped blade has curved profile and variable thickness to provide higher air delivery and less noise. The aerofoil shaped blade has twist angle is in range of 19o to 11o which decreases non-uniformly from rotor end to tip end of the blade. Further, the aerofoil shaped blade has thickness at rotor end in range of 7 to 9mm and at tip end in the range of 1 to 3mm. The aerofoil shaped blade has lift angle of 10o with reference to horizontal axis of the blade. Due to the curved profile, aerofoil shaped profile, and variable thickness with non-uniform optimized twist angle provides higher air delivery at fan sweep of 1300mm.
[0025] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be constructed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0026] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0027] Fig. 1 illustrates structure of ceiling fan with the fan blade, in accordance with the present subject matter. The ceiling fan 100 has a plurality of ceiling fan blade 101, motor 102, hanging rod 104, and canopies 103. The canopies 103 of the fan and hanging rod 104 are designed for matching with motor profile to make fan more attractive. Further, the plurality of ceiling fan blade 101 is three in number. It can be more and less as per the requirement. The plurality of ceiling fan blade 101 is mounted on hub of the motor 102 which is a rotor. The mounting can be done by screw. The plurality of ceiling fan blade 101 is mounted in such a manner that is looks smooth circumference at the hub.
[0028] Fig. 2 illustrates lift angle of the aerofoil shaped blade, in accordance with the present subject matter. The ceiling fan blade 101 has aerofoil shaped profile. The ceiling fan blade 101 has a tip end 101a and a rotor end 101b. The ceiling fan blade 101 has a winglet 101d at the tip end 101a to reduce vortex. The winglet 101d maintains the air pressure at the tip end. The ceiling fan blade 101 is mounted at the rotor of the motor 102 at the rotor end 101b. The tip end 101a rotates about central axis of the motor 102 during movement of the rotor. The aerofoil shaped ceiling fan blade 101 is thicker at the rotor end 101b tapering down to a thinner at the tip end 101a for providing high lift and low drag. As shown in the figure 2, aerofoil shaped fan blade 101 has lift angle 201 of 10o with reference to horizontal axis of the fan for higher air delivery. The lift angle 201 increases spread of air in the ceiling fan 100.
[0029] Fig. 3 illustrates twist angle of the aerofoil shaped blade, in accordance with an embodiment of the present subject matter. The aerofoil shaped fan blade 101 has twist angle 301 in range of 19o to 11o along length of the ceiling fan blade. The twist angle 301 decreases non-uniformly from the rotor end 101b to the tip end 101a of the aerofoil shaped fan blade 101. The aerofoil shaped fan blade 101 has curved profile along with length instead of flat profile as in existing fan blades. The curved profile of the aerofoil shaped fan blade 101 decreases the drag.
[0030] Fig. 4 illustrates variable twist angle according to thickness and length of the aerofoil shaped blade, in accordance with an embodiment of the present subject matter. The aerofoil shaped fan blade 101 has a circular edge 101c at the rotor end 101b. The circular edge 101c fitted with the motor 102 of the ceiling fan 100. Similarly, the circular edges 101c of the other two aerofoil shaped fan blades fitted with the motor 102 of the ceiling fan 100 to provide a smooth surface without any cut at rotor area. The circular edges 101c cover the complete circumference of the rotor/motor 102 to provide a smooth circumference. The present aerofoil shaped fan blade has four sections AA, BB, CC, and DD at equal distance from each other. The sections AA, BB, CC, and DD are at a distance of 115 mm from each other. Further, the section AA is at 140mm from the circular edge 101c of the fan blade 101. The aerofoil shaped fan blade 101 is curved along the length as shown in the figures 3 and 5. The twist angle 301 decreases non-uniformly from the rotor end 101b to the tip end 101a of the aerofoil shaped fan blade 101. As shown in the figure 5, the section AA which is closer to the rotor end 101b has highest twist angle of approximately 19o. The section BB has twist angle of approximately 14o. The section CC has twist angle of approximately 12o. The section DD has twist angle of approximately 11o. There is non uniform twist rate along the length of the blade. Even the twist rate is non-uniform in the sections.
[0031] As shown in the figure 5, the aerofoil shaped fan blade 101 has variable thickness which decreases from the rotor end 101b to the tip end 101a. Similarly, the aerofoil shaped fan blade 101 is wider at the rotor end 101b and narrow down towards the tip end 101a. The thickness of the aerofoil shaped fan blade 101 is at rotor end 101b is in range of 7 to 9 mm, preferably 8mm. The thickness of the aerofoil shaped fan blade 101 is at the tip end (101b) is in range of 1 to 3 mm, preferably 2mm. The thickness at rotor end is more as compared to the tip end. The thickness at rotor end is designed to give higher air delivery and to allow blade fitment with the motor 102 and to withstand the blade in static as well as dynamic load without sagging/ breaking. The rotor end 101b has a rib structure 101e to provide strength to the aerofoil shaped fan blade 101 at the rotor end. Further, a cover 101f is provided to cover the rib structure 101e to avoid deposition of any dust in the rib structure 101e. The cover 101f is made of plastic material.
[0032] The aerofoil shaped fan blade 101 has blade length of approximately 645 mm and fan sweep of 1300mm. The aerofoil shaped fan blade 101 is compounded polymer blade which is made in single mold. Further, the aerofoil shaped fan blade 101 is painted with Polyurethane (PU) to increase shine and aesthetic appearance of the ceiling fan.
[0033] The present ceiling fan 100 with the aerofoil shaped fan blade 101 provides higher air delivery of 300 CMM at full speed. Further, the present ceiling fan 100 has improved noise performance with 55dB(A) at one meter below from the center axis of the fan.
[0034] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.