The invention relates to a rotary wing aircraft. In particular, the invention relates to a dual rotor coaxial wing aircraft. The dual rotor coaxial wing aircraft can be made into a variety of forms, unmanned aerial vehicle being one of them.
BACKGROUND OF THE INVENTION
Dual rotor coaxial wing aircrafts have been under development for almost 80 years. Recently, dual rotor coaxial wing aircrafts have been used for making unmanned aerial vehicle (UAV) which are widely used for aerial reconnaissance, monitoring, communication, anti-submergence, electronic interference, aerial photography, agriculture, plant protection, miniature self-timer, express transportation, disaster relief, wild animal observation, infectious disease monitoring, surveying and mapping, news reporting, power inspection, disaster relief, movie and television shooting and the like.
A dual rotor coaxial wing aircraft generally comprises of a central non-rotating shaft acting as a backbone to a plurality of rotors systems, which rotate about a common axis of rotation. Each rotor system, in general, comprises its respective rotor blades. The dual rotor coaxial wing aircraft further comprises two motors to drive the rotor systems and at least one speed controller to control the speed of the two motors. The two motors are generally connected to the blades of the respective rotor systems by means of a drive train such as gear and other linking mechanisms. Since each motor imparts vibrations, the drive train experiences stress, which reduces the lifetime of the drive train. The vibration also affects the dual rotor coaxial wing aircrafts during takeoffs, landings and during other maneuverings. Generally to reduce the vibrations, the motors are mounted on plates which have through hole (to allow the motor's output shaft to traverse there through). Sometimes, resilient members such as washer / bush are used for interconnecting the motor to the plate to reduce transmission of the vibration to other parts. Although this approach is successful to some extent, improvement in the same are desired.

Further, the dual rotor coaxial wing aircraft comprises two pitch controllers for controlling the pitch of the rotors. Each pitch controller comprises a swash plate connected to the rotor blades and actuators connected to the swash plate and configured to actuate the swash plate. A variety of swash plates are available in the market. However, it would be beneficial to provide an efficient mechanism for controlling the cyclic and collective pitch of the rotor blades using a single swash plate, which therefore necessitates modification of the swash plate.
Also, it has been observed that the swash plate is connected to the actuators via linking mechanism. However, because of the vibrations and the repeated actuation of the swash plate by the actuators, the linking mechanism faces a lot of wear and tear, which ultimately affects the life of the linking mechanism. Therefore, a need to modify the linking mechanism has also been felt.
Therefore, there is a need to modify multiple aspects of a conventional dual rotor coaxial wing aircraft.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts in a simplified format that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention, and nor is it intended for determining the scope of the invention.
The present invention relates to a dual rotor coaxial wing aircraft, comprising: a shaft element supporting a first set of blades and a second set of blades in a spaced apart relationship; a first motor coupled to the first set of blades and being adapted to rotate the first set of blades in a first direction about the shaft element; and a second motor coupled to the second set of blades and being adapted to rotate the second set of blades in a second direction about the shaft element; the first and the second motors are placed in between a first horizontal wall, a second horizontal wall, and a circumferential wall connecting the first and the second horizontal walls; the first horizontal wall comprising a first aperture for

allowing an output shaft of the first motor to traverse there through in a first direction, a second aperture for allowing the shaft element to traverse there through, a third aperture for receiving a body portion of the second motor, and at least one vibration dampening structure; and the second horizontal wall comprising a first aperture for allowing an output shaft of the second motor to traverse there through in a second direction, a second aperture for allowing the shaft element to traverse there through, a third aperture for receiving a body portion of the first motor, and at least one vibration dampening structure.
In another embodiment, the present invention relates to a dual rotor coaxial wing aircraft, comprising: a shaft element supporting a first set of blades and a second set of blades in a spaced apart relationship; a first motor coupled to the first set of blades and being adapted to rotate the first set of blades in a first direction about the shaft element; a second motor coupled to the second set of blades and being adapted to rotate the second set of blades in a second direction about the shaft element; and a pitch controller for controlling the pitch of one of the first set of blades and the second set of blades, the pitch controller comprising: a swash plate moveably supported by the shaft element; plurality of actuators for imparting movement to the swash plate; a first set of linking members connecting the swash plate and the plurality of actuators; and a second set of linking members connecting the swash plate with one of the first set of blades and the second set of blades; each linking member comprises: a rod element defining a proximal end and a distal end; a pair of rod end joints attached to the proximal end and the distal end of the rod element; each of the proximal and distal end of the rod element including two sets of external threads and the rod end joint comprises two sets of internal threads for connecting to the two sets of external threads provided on the rod element.
In yet another embodiment, the present invention relates to a dual rotor coaxial wing aircraft, comprising: a shaft element supporting a first set of blades and a second set of blades in a spaced apart relationship; a first motor coupled to the first set of blades and being adapted to rotate the first set of blades in a first direction about the shaft element; a second motor coupled to the second set of blades and being adapted to rotate the second set of blades in a second direction about the shaft element; and a pitch controller for controlling

the pitch of one of the first set of blades and the second set of blades, the pitch controller comprising: a swash plate moveably supported by the shaft element; plurality of actuators for imparting movement to swash plate; a first set of linking members connecting the swash plate and the plurality of actuators; and a second set of linking members connecting the swash plate with one of the first set of blades and the second set of blades; the swashplate comprises: a non-rotating ring moveably supported by the shaft element; a rotating ring coupled to the non-rotating ring such that (a) the rotating ring rotates with respect to the non-rotating ring; (b) both the rings exhibit motion along the axial direction of the shaft as one unit; and (c) both the rings exhibit tilting motion with respect to the axis of the shaft as one unit; the rotating ring being coupled to the one of the first set of blades and the second set of blades via the second set of linking members; the non-rotating ring defines at least three joining points for receiving respective first set of linking members thereby connecting the non-rotating ring to the respective actuators.
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is to be appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.
Brief Description of Figures:
These and other features, aspects, and advantages of the present invention will become
better understood when the following detailed description is read with reference to the
accompanying drawings in which like characters represent like parts throughout the
drawings, wherein:
FIGURE 1 illustrates a perspective view of the Unmanned Aerial Vehicle in accordance
with an embodiment of the present invention;
FIGURE 2 illustrates a perspective view of the Unmanned Aerial Vehicle after removal of
the body portion in accordance with an embodiment of the present invention;

FIGURE 3 illustrates an exploded view of the motor container in accordance with an
embodiment of the present invention;
FIGURE 4 illustrates a top view of the horizontal plate in accordance with an embodiment
of the present invention;
FIGURE 5 illustrates a perspective view of the linking member in accordance with an
embodiment of the present invention;
FIGURE 6 illustrates a perspective view of the linking member in accordance with an
embodiment of the present invention;
FIGURES 7(a), 7(b), and 7(c) illustrate a various view of the rod end joints in accordance
with an embodiment of the present invention;
FIGURE 8 illustrates a perspective view of the closer view of the pitch controller in
accordance with an embodiment of the present invention;
FIGURE 9 illustrates a perspective view of the swash plate in accordance with an
embodiment of the present invention; and
FIGURE 10 illustrates a perspective view of the non-rotating ring in accordance with an
embodiment of the present invention.
Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
Detailed Description of the Invention:
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as

illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
Reference throughout this specification to "an aspect", "another aspect" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover anon-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

Now referring to Figure 1, there is illustrated an external view of the dual rotor coaxial wing aircraft, in accordance with an embodiment of the invention. The dual rotor coaxial wing aircraft is shown in the form of an unmanned aerial vehicle (100). The unmanned aerial vehicle (100) comprises a first set of blades (102) and a second set of blades (104). The unmanned aerial vehicle (100) carries a first payload (106), which is assists in maintaining communication between the unmanned aerial vehicle (100) and a remote location. The unmanned aerial vehicle (100) may carry a second payload (108). The second payload (108) is chosen on the basis of the purpose for which the unmanned aerial vehicle (100) is constructed. For instance, the unmanned aerial vehicle (100) can comprise a second payload (108) which provides a desired functionality for aerial reconnaissance, monitoring, communication, anti-submergence, electronic interference, aerial photography, agriculture, plant protection, miniature self-timer, express transportation, disaster relief, wild animal observation, infectious disease monitoring, surveying and mapping, news reporting, power inspection, disaster relief, movie and television shooting and the like. The unmanned aerial vehicle (100) comprises driving mechanism which is housed within one or more body portions (110). The unmanned aerial vehicle (100) may comprise landing system (112). In an embodiment of the invention, the landing system (112) may be of retractable type.
Now referring to Figure 2, there is illustrated a view of the unmanned aerial vehicle (100) after removal of the body portions (110), in accordance with an embodiment of the invention. It can be that the first set of blades (102) and the second set of blades (104) are supported by a shaft element (114) in a spaced apart relationship.
The driving mechanism of the unmanned aerial vehicle (100) comprises a first motor (116) coupled to the first set of blades (102) and being adapted to rotate the first set of blades (102) in a first direction about the shaft element (114). The driving mechanism of the unmanned aerial vehicle (100) comprises a second motor (118) coupled to the second set of blades (104) and being adapted to rotate the second set of blades (104) in a second direction about the shaft element (114). In particular, the first motor (116) is coupled to the first set of blades (102) using a first motion transfer mechanism (119a) and the second motor (118) coupled to the second set of blades (104) using a second motion transfer mechanism (119b).

In an embodiment, the first motion transfer mechanism (119a) and the second motion transfer mechanism (119b) may employ any mechanism such as gears, chains, belts or any other mechanism. In a preferred embodiment of the invention, the first motion transfer mechanism (119a) and the second motion transfer mechanism (119b) are gears. The gears may be selected from a group comprising spur gear, helical gear, double helical or herringbone gear, bevel gear, rack and pinion gear, worm gear helical gears, preferably helical gears. The helical gears, in one embodiment, could be 12 degree helical gears.
The driving mechanism further comprises a pitch controller (120). The pitch controller (120) may be coupled to either the first set of blades (102) or the second set of blades (104) and controls the pitch angel of the connected blade. In an embodiment of the invention, the pitch controller (120) is coupled to the second set of blades (104) and controls the cyclic and collective pitch of the second set of blades (104). By controlling the cyclic and collective pitch of the second set of blades (104), the movement in the upward and downward directions (ascent / descent) can be controlled. In another embodiment (not illustrated), the pitch controller is coupled to the first set of blades and controls the cyclic and collective pitch of the first set of blades. By controlling the cyclic and collective pitch of the first set of blades, the movement in the upward and downward directions (ascent / descent) can be controlled.
In particular, the pitch controller (120) comprises a swash plate (122) moveably supported by the shaft element (114); plurality of actuators (124) for imparting movement to the swash plate (124); a first set of linking members (126) connecting the swash plate (122) and the plurality of actuators (124); and a second set of linking members (128) connecting the swash plate (122) with the second set of blades (104).
The driving mechanism further comprises a motor controller (130) that controls the operating speed of the first motor (116) and the operating speed of the second motor (118).
The unmanned aerial vehicle (100) further comprises master controller (132). The master controller (132) controls the operation of the motor controller (130), the operation of the

pitch controller (120); and other electronic elements forming part of the unmanned aerial vehicle (100). In particular, the master controller (132) controls the operation of the plurality of actuators (124) forming part of the pitch controller (120).
In an embodiment, the master controller (132) controls via the motor controller (130) the speed of the second motor (118). Also, the master controller (132) controls operation of the plurality of actuators (124). By controlling the speed of the second motor (118) and the operation of the plurality of actuators (124); the rate of ascent / descent of the unmanned aerial vehicle can be controlled. In addition to the above, the master controller (132) controls via the motor controller (130) the speed of the first motor (116) and thus, controls the rightward-leftward movement of the unmanned aerial vehicle.
In another embodiment of the invention (not illustrated), the master controller (132) controls via the motor controller (130) the speed of the first motor (116). Also, the master controller (132) controls operation of the plurality of actuators (124) forming part of the pitch controller (120). By controlling the speed of the first motor (116) and the operation of the plurality of actuators (124); the rate of ascent / descent of the unmanned aerial vehicle can be controlled. In addition to the above, the master controller (132) controls via the motor controller (130) the speed of the second motor (118) and thus, controls the rightward-leftward movement of the unmanned aerial vehicle.
The first set of blades (102) and the second set of blades (104) are configured to pivot or rotate independently with respect to the shaft element (114), when the first and the second motors (116, 118) are not operating. The first and second set of blades may be of equal or unequal length. In a preferred embodiment, first and second set of blades are of unequal length as unequal length reduce the chance that the blades will contact one another as they fold at high speed during a crash-landing.
In an embodiment, the first motor (116) and the second motor (118) may be any type of motor (e.g., an electric, gasoline-powered or any other type of motor) capable of generating sufficient rotational speeds of the corresponding rotor blades, to provide lift and/or thrust

forces to the UAV and any engaged payload. For example, in some implementations, one or more of the motors may include a brushless direct current (DC) motor such as an outrunner brushless motor or an inrunner brushless motor.
In some applications, especially where flight times are short and economy is a factor (for example, in a short-range disposable munition) low-cost brushed motors (i.e. motors having carbon brushes and rotating commutators) may be used in place of one high-cost brushless motor to turn rotor hub.
Now coming to the first aspect of the invention, as shown in Figure 3, the first and the second motors (116, 118) are placed in between a first horizontal wall (134), a second horizontal wall (136), and a circumferential wall (138). The circumferential wall (138) is located between the first and the second horizontal walls (134, 136). In an embodiment of the invention, an output shaft (140) of the first motor (116) traverses through the first horizontal wall (134) in a first direction and an output shaft (142) of the second motor (118) traverses through the second horizontal wall (136) in a second direction.
Now referring to Figure 4, which is a top view of the first horizontal wall (134), in an embodiment of the invention, the first horizontal wall (134) comprises a first aperture (144) for allowing the output shaft (140) of the first motor (116) to traverse there through, a second aperture (146) for allowing the shaft element (114) to traverse there through, a third aperture (148) for receiving a body portion (not specifically numbered) of the second motor (118), and at least one vibration dampening structure (150). In a particular embodiment of the invention, the at least one vibration dampening structure (150) is in the form of a plurality of spaced apart walls (152, 154) emanating from the second aperture (146) to about a peripheral portion of the first horizontal wall (134).
Although not shown, the second horizontal wall (136) has a construction which is identical to the construction of the first horizontal wall (134). In other words, the second horizontal wall comprises a first aperture (144) for allowing the output shaft (142) of the second motor (118) to traverse there through, a second aperture (146) for allowing the shaft element (114)

to traverse there through, a third aperture (148) for receiving a body portion of the first motor (116), and at least one vibration dampening structure (150). In a particular embodiment of the invention, the at least one vibration dampening structure (150) is in the form of a plurality of spaced apart walls (152, 154) emanating from the second aperture (146) to about a peripheral portion of the second horizontal wall (136).
It has been surprisingly observed that by providing the third aperture (148) for receiving a body portion of the first motor (116), and at least one vibration dampening structure (150); a combined synergistic effect is obtained in terms of reduction in the amount of vibrations which propagate to other parts of the UAV (100).
Now coming to the second aspect of the invention, as shown in Figure 5, the linking member (126, 128) in an embodiment of the invention comprise a rod element (156) and a pair of rod end joints (158) attached to the rod element.
As shown in particularly in Figure 6, the rod element (156) defines a proximal end (160) and a distal end (162). Each of the proximal as well as the distal end of the rod element includes two sets of external threads (164, 166). The two sets of external threads (164, 166) are formed along the length of the rod. In particular, the first set of external threads (164) are formed at a portion of the rod element having a diameter of "Dl" while the second set of external threads (166) are formed at a portion of the rod element having a diameter of "D2", wherein Dl is not equal to D2. In a more preferred embodiment of the invention, the value of Dl is less than the value of D2.
As shown in Figure 7 (a), 7(b) and 7(c), the rod end joints (158) comprises an eye portion (168) and a rod connection portion (170). The rod connection portion (170) comprises two sets of internal threads (172 and 174) for connecting to the two sets of external threads provided on the rod element. In particular, the first set of internal threads (172) are formed at a portion of the rod element having a diameter of "Dl" while the second set of internal threads (174) are formed at a portion of the rod element having a diameter of "D2", wherein

Dl is not equal to D2. In a more preferred embodiment of the invention, the value of Dl is less than the value of D2.
It has been surprisingly observed that the linking member having the aforesaid construction, is able to withstand vibrations and the repeated actuation and hence, the wear and tear is substantially reduced which may contribute to increased life of the linking mechanism and hence, the UAV.
Now referring to Figure 8, there is illustrated a closer view of the pitch controller (120). The pitch controller (120) comprises a swash plate (122) moveably supported by the shaft element (114); three actuators (124i, 1242, 1243) for imparting movement to the swash plate (124); three linking members (126i, 1262, I263) connecting the swash plate (122) and the three actuators (124i, 1242, 1243); and two linking members (128i, 1282) connecting the swash plate (122) with the second set of blades (104).
Now referring particularly to Figure 9, the swash plate (122) comprises a non-rotating ring (176) moveably supported by the shaft element (114); and a rotating ring (178) coupled to the non-rotating ring (176). The nature of coupling between the non-rotating ring (176) and the rotating ring (178) is such that (a) the rotating ring (178) rotates with respect to the non-rotating ring (176); (b) both the rings (176, 178) exhibit motion along the axial direction of the shaft element (114) as one unit; and (c) both the rings (176, 178) exhibit tilting motion with respect to the axis of the shaft element (114) as one unit. To enable the rotating ring (178) to rotate with respect to the non-rotating ring (176), ball bearings (180) are provided.
Referring to Figures 8 and 9 together, it can be seen that the rotating ring (178) is coupled to the one of the first set of blades (102) and the second set of blades (104) via the second set of linking members (128i, 1282). In particular, the rotating ring (178) is coupled to the second set of blades (104) via the second set of linking members (128i, 1282).
Now referring particularly to Figure 10; the non-rotating ring (176) defines three joining points (182i, 1822, I823) for receiving a respective linking member (126i, 1262, 1263) thereby connecting the non-rotating ring to the respective actuators (124i, 1242, 1243). When

the three actuators (124i, 1242, 1243) are moved by equal amount, both the rings (176, 178) exhibit motion along the axial direction of the shaft element (114) as one unit. On the other hand, when the three actuators (124i, 1242, 1243) are moved by un-equal amounts, both the rings (176, 178) exhibit tilting motion with respect to the axis of the shaft element (114) as one unit.
While Figures 8, 9 and 10 illustrate use of three actuators (124i, 1242, 1243), three linking members (126i, 1262, 1263) and three joining points (182i, 1822, I823) on the non-rotating ring (176); it is possible to increase their numbers. For instance, it is possible to provide four actuators (124), four linking members of the first set (126) and four joining points (182) on the non-rotating ring (176). However, the minimum number actuators (124), linking members of the first set (126) and joining points (182) on the non-rotating ring (176) should be equal to three. Also, it has been found that providing more than six actuators (124), six linking members of the first set (126) and six joining points (182) on the non-rotating ring (176) may increase the complexity of the UAV and may not provide any substantial benefit in terms of maneuvering capability.
In a preferred embodiment of the invention, the joining points (182) are equidistantly placed on the non-rotating ring (176). For instance, the angular displacement between the joining points (182i, 1822, I823) is 120°. Such a placement increases the stability of the swash plate (122) while exhibiting motion with respect to the shaft element (114).
In an embodiment of the invention, the dual rotor coaxial wing aircraft comprises a power module comprising, for example, a battery, fuel cell, or hybrid gas-electric generator is provided to supply electric power to the motors, actuators, and controllers and like. In another embodiment, multiple power modules are provided for additional energy capacity during flight. Flight times of rotary wing aircraft can be adjusted by adjusting the number of power modules carried in flight. In an embodiment of the invention, the shaft element acts as a conduit for electrical wiring for power transmission.

The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processing may be changed and are not limited to the manner described herein. In addition, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.
While certain present preferred embodiments of the invention have been illustrated and described herein, it is to be understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.

WE CLAIM:

1. A dual rotor coaxial wing aircraft, comprising:
a shaft element (114) supporting a first set of blades (102) and a second set of blades
(104) in a spaced apart relationship;
a first motor (116) coupled to the first set of blades (102) and being adapted to rotate
the first set of blades (102) in a first direction about the shaft element (114); and
a second motor (118) coupled to the second set of blades (104) and being adapted to
rotate the second set of blades (104) in a second direction about the shaft element
(114);
the first and the second motors (116, 118) are placed in between a first horizontal
wall (134), a second horizontal wall (136), and a circumferential wall (138)
connecting the first and the second horizontal walls (134, 136);
the first horizontal wall (134) comprising a first aperture (144) for allowing an output
shaft (140) of the first motor (116) to traverse there through in a first direction, a
second aperture (146) for allowing the shaft element (114) to traverse there through,
a third aperture (148) for receiving a body portion of the second motor (118), and at
least one vibration dampening structure (150); and
the second horizontal wall (136) comprising a first aperture (144) for allowing an
output shaft (142) of the second motor (118) to traverse there through in a second
direction, a second aperture (146) for allowing the shaft element (114) to traverse
there through, a third aperture (148) for receiving a body portion of the first motor
(116), and at least one vibration dampening structure (150).
2. The dual rotor coaxial wing aircraft as claimed in claim 1, further comprising a pitch
controller (120) for controlling the pitch of one of the first set of blades (102) and the
second set of blades (104), the pitch controller (120) comprising: a swash plate (122)
moveably supported by the shaft element (114); plurality of actuators (124) for
imparting movement to swash plate (122); a first set of linking members (126)
connecting the swash plate (122) and the plurality of actuators (124); and a second

set of linking members (126) connecting the swash plate (122) with one of the first
set of blades (102) and the second set of blades (104);
each linking member (126, 128) comprises:
a rod element (156) defining a proximal end (160) and a distal end (162);
a pair of rod end joints (158) attached to the proximal end (160) and the distal end
(162) of the rod element (156);
each of the proximal and distal end (160, 162) of the rod element (156) including
two sets of external threads (164, 166) and the rod end joint (158) comprises two sets
of internal threads (172, 174) for connecting to the two sets of external threads (164,
166) provided on the rod element (156).
3. The dual rotor coaxial wing aircraft as claimed in claim 1, wherein the swash plate
(122) comprises:
a non-rotating ring (176) moveably supported by the shaft element (114);
a rotating ring (178) coupled to the non-rotating ring (176) such that (a) the rotating
ring (178) rotates with respect to the non-rotating ring (176); (b) both the rings (176,
178) exhibit motion along the axial direction of the shaft element (114) as one unit;
and (c) both the rings (176, 178) exhibit tilting motion with respect to the axis of the
shaft element (114) as one unit;
the rotating ring (178) being coupled to the one of the first set of blades (102) and the
second set of blades (104) via the second set of linking members (128i, 1282);
the rotating ring (178) defines at least three joining points (182i, 1822,1823) for
receiving respective first set of linking members (126i, 1262, 1263) thereby
connecting the non-rotating ring to the respective actuators (124i, 1242, 1243).
4. A dual rotor coaxial wing aircraft, comprising:
a shaft element (114) supporting a first set of blades (102) and a second set of blades (104) in a spaced apart relationship;
a first motor (116) coupled to the first set of blades (102) and being adapted to rotate the first set of blades in a first direction about the shaft element (114);

a second motor (118) coupled to the second set of blades (104) and being adapted to
rotate the second set of blades (104) in a second direction about the shaft element
(114); and
a pitch controller (120) for controlling the pitch of one of the first set of blades (102)
and the second set of blades (104), the pitch controller (120) comprising: a swash
plate (122) moveably supported by the shaft element (114); plurality of actuators
(124) for imparting movement to swash plate (122); a first set of linking members
(126) connecting the swash plate (122) and the plurality of actuators (124); and a
second set of linking members (128) connecting the swash plate (122) with one of
the first set of blades (102) and the second set of blades (104);
each linking member (126, 128) comprises:
a rod element (156) defining a proximal end (160) and a distal end (162);
a pair of rod end joints (158) attached to the proximal end and the distal end of the
rod element (156);
each of the proximal and distal end of the rod element including two sets of external
threads (164, 166) and the rod end joint (158) comprises two sets of internal threads
(172, 174) for connecting to the two sets of external threads (164, 166) provided on
the rod element (156).
5. The dual rotor coaxial wing aircraft as claimed in claim 4, wherein the first and the
second motors (116, 118) are placed in a between a first horizontal wall (134), a second horizontal wall (136), and a circumferential wall (138) connecting the first and the second horizontal walls (134, 136) such that an output shaft (140) of the first motor (116) to traverse through the first horizontal wall (134) in a first direction and an output shaft (142) of the second motor (118) traverses through the second horizontal wall (136) of the chamber in a second direction;
the first horizontal wall (134) comprising a first aperture (144) for allowing the output shaft (140) of the first motor (116) to traverse there through, a second aperture (146) for allowing the shaft element (114) to traverse there through, a third aperture

(148) for receiving a body portion of the second motor (118), and at least one vibration dampening structure (150); and
the second horizontal wall (136) comprising a first aperture (144) for allowing the output shaft (142) of the second motor (118) to traverse there through, a second aperture (146) for allowing the shaft element (114) to traverse there through, a third aperture (148) for receiving a body portion of the first motor (116), and at least one vibration dampening structure (150).
6. The dual rotor coaxial wing aircraft as claimed in claim 4, wherein the swash plate
(122) comprises:
a non-rotating ring (176) moveably supported by the shaft element (114);
a rotating ring (178) coupled to the non-rotating ring (176) such that (a) the rotating
ring (178) rotates with respect to the non-rotating ring (176); (b) both the rings (176,
178) exhibit motion along the axial direction of the shaft element (114) as one unit;
and (c) both the rings (176, 178) exhibit tilting motion with respect to the axis of the
shaft element (114) as one unit;
the rotating ring (178) being coupled to the one of the first set of blades (102) and the
second set of blades (104) via the second set of linking members;
the rotating ring defines at least three joining points for receiving respective first set
of linking members (126) thereby connecting the non-rotating ring (176) to the
respective actuators (124).
7. A dual rotor coaxial wing aircraft, comprising:
a shaft element (114) supporting a first set of blades (102) and a second set of blades
(104) in a spaced apart relationship;
a first motor (116) coupled to the first set of blades (102) and being adapted to rotate
the first set of blades in a first direction about the shaft element (114);
a second motor (118) coupled to the second set of blades (104) and being adapted to
rotate the second set of blades in a second direction about the shaft element (114);
and

a pitch controller (120) for controlling the pitch of one of the first set of blades (102)
and the second set of blades (104), the pitch controller (120) comprising: a swash
plate (122) moveably supported by the shaft element (114); plurality of actuators
(124) for imparting movement to swash plate (122); a first set of linking members
(126) connecting the swash plate (122) and the plurality of actuators (124); and a
second set of linking members (128) connecting the swash plate (122) with one of
the first set of blades (102) and the second set of blades (104);
the swash plate (122) comprises:
a non-rotating ring (176) moveably supported by the shaft element (114);
a rotating ring (178) coupled to the non-rotating ring (176) such that (a) the rotating
ring (178) rotates with respect to the non-rotating ring (176); (b) both the rings (176,
178) exhibit motion along the axial direction of the shaft element (114) as one unit;
and (c) both the rings (176, 178) exhibit tilting motion with respect to the axis of the
shaft element (114) as one unit;
the rotating ring (178) being coupled to the one of the first set of blades (102) and the
second set of blades (104) via the second set of linking members (128i, 1282);
the rotating ring (178) defines at least three joining points (182i, 1822,1823) for
receiving respective first set of linking members (126i, 1262, I263) thereby
connecting the non-rotating ring (176) to the respective actuators (124).
8. The dual rotor coaxial wing aircraft as claimed in claim 7, wherein the first and the
second motors (116, 118) are placed in a between a first horizontal wall (134), a second horizontal wall (136), and a circumferential wall (138) connecting the first and the second horizontal walls (134, 138) such that an output shaft (140) of the first motor (116) to traverse through the first horizontal wall (134) in a first direction and an output shaft (142) of the second motor (118) traverses through the second horizontal wall (136) of the chamber in a second direction;
the first horizontal wall (134) comprising a first aperture (144) for allowing the output shaft (140) of the first motor (116) to traverse there through, a second aperture (146) for allowing the shaft element (114) to traverse there through, a third aperture

(148) for receiving a body portion of the second motor (118), and at least one vibration dampening structure (150); and
the second horizontal wall (136) comprising a first aperture (144) for allowing the output shaft (142) of the second motor (118) to traverse there through, a second aperture (146) for allowing the shaft element (114) to traverse there through, a third aperture (148) for receiving a body portion of the first motor (116), and at least one vibration dampening structure (150).
9. The dual rotor coaxial wing aircraft as claimed in claim 7, each linking member
comprises:
a rod element (156) defining a proximal end (160) and a distal end (162); a pair of rod end joints (158) attached to the proximal end and the distal end of the rod element (156); each of the proximal and distal end of the rod element including two sets of external threads (164, 166) and the rod end joint comprises two sets of internal threads (172, 174) for connecting to the two sets of external threads (164, 166) provided on the rod element (156).