Description:Field of Invention
The present invention belongs to the co-axial propellers for Unmanned aerial vehicles
Background of the Invention
The co-axial propellers, also known as dual-rotor or counter-rotating propellers, are a type of propulsion system commonly used in UAVs and other aircraft. In a co-axial setup, two propellers are mounted on the same axis, with one placed above the other. Both propellers rotate in opposite directions, which creates a number of advantages for UAV design and performance. The counter-rotating propellers produce equal and opposite torques, which cancel each other out. This reduces the UAV's tendency to spin or rotate uncontrollably, providing better stability during flight. One of the main advantages of co-axial propellers is enhanced stability and control. The counter-rotating propellers produce equal and opposite torques, which cancel each other out. This reduces the UAV's tendency to spin or rotate uncontrollably, providing better stability during flight.
Co-axial propellers can provide greater lifting capability compared to single-rotor systems. The two sets of propellers working together can generate more thrust, allowing the UAV to carry heavier payloads or fly in more challenging conditions, such as high altitudes or strong winds. Simplified Mechanical Design: Compared to traditional quadcopters that use four separate motors and propellers, co-axial UAVs have a simpler mechanical design with only two motors. This can lead to reduced weight, fewer moving parts, and potentially lower maintenance requirements. Co-axial propellers can be more efficient in terms of power consumption and flight time. The counter-rotating system helps to reduce energy losses, resulting in longer flight times and better overall battery efficiency. The co-axial design allows for a more compact UAV body, making it easier to maneuver in tight spaces or indoor environments. This makes co-axial UAVs suitable for applications like search and rescue operations or inspections in confined areas. The counter-rotating propellers can also help in reducing the overall noise level produced by the UAV. This can be advantageous in scenarios where noise needs to be minimized, such as wildlife monitoring or surveillance operations.
The patent US8931729B2 ,pertains to a system for increasing the thrust and power capabilities of a side by side vertical takeoff and landing vehicle and decrease loses in power and thrust of coaxial rotors. The Ducted fan vertical take-off and landing vehicle, US20060226281A1 overcomes the turning radius and stopping ability problems inherit in current flying vehicles by the layout of the ducted fan units and the benefit of the ducted fan units maneuvering abilities. Hovering aerial vehicle with removable rotor arm assemblies, US20090283629A1, provides a hovering aerial vehicle with removable rotor arms and protective shrouds. This innovation US2438661A pertains to a double propeller system designed for gyroplanes and similar aircraft. In this system, two horizontal propellers are employed to keep the aircraft airborne. These propellers spin in opposing directions around a vertical axis, effectively counteracting the torque on the engine that powers them. The patent, US2282266A focus of the invention is on the configuration of structures in which airplane propellers or similar devices are situated along the same axis as the propeller shaft. These propellers are also connected to and driven by this shaft.
The invention presented here coaxial propeller for Unmanned aerial vehicle and will be using the fundamental mechanics and mechanisms for the morphing wing applications. The design is simple, easy to manufacture and assemble with less weight penalty. It provides high thrust to weight ratio to the UAV.
Summary of the Invention
This invention focus on the coaxial propellers used in the unmanned aerial vehicles. Co-axial propellers, also known as dual-rotor or counter-rotating propellers, are a type of propulsion system commonly used in UAVs and other aircraft. In this co-axial setup, two propellers are mounted on the same axis, with one placed above the other. Both propellers rotate in opposite directions, which creates a number of advantages for UAV design and performance. The counter-rotating propellers produce equal and opposite torques, which cancel each other out. This reduces the UAV's tendency to spin or rotate uncontrollably, providing better stability during flight. Compared to traditional quad copters that use four separate motors and propellers, co-axial UAVs have a simpler mechanical design with only two motors. This can lead to reduced weight, fewer moving parts, and potentially lower maintenance requirements. Co-axial propellers can be more efficient in terms of power consumption and flight time. The counter-rotating propellers can also help in reducing the overall noise level produced by the UAV. The components of the coaxial propeller assembly are fabricated with 3D printing. This design is simple and easy to assemble and cost effective. Propellers are mounted on the inner and outer hub and the lower race is attached to the engine mount. This type of design ensures smooth flow of load from the propeller to the engine mount. The propeller is flushed into hub and the hub is mounted on the motor shaft. The aerodynamics can cause varying load conditions for the upper and lower propellers, and these loads are then transferred from the engine mount to the fuselage.
Brief Description of Drawings
The invention will be described in detail with reference to the exemplary embodiments shown in the figures wherein:
Figure 1: Coaxial propeller Lower hub assembly
Figure 2: Coaxial propeller Assembly with all sub assemblies
Figure 3: Coaxial propeller Assembly
Detailed Description of the Invention
The present design reveals structural arrangement of coaxial propeller. The co-axial propellers also referred to as dual-rotor or counter-rotating propellers, represent a propulsion system commonly employed in UAVs and other aircraft. In this configuration, two propellers are positioned along the same axis, with one located above the other. Both propellers rotate in opposing directions, yielding a range of advantages for UAV performance and design. The counter-rotating propellers generate torque forces that are equal in magnitude and opposite in direction, effectively nullifying each other. This counteraction curbs the UAV's inclination to spin or undergo uncontrolled rotation, thus enhancing stability during flight. In contrast to conventional quadcopters employing four distinct motors and propellers, co-axial UAVs exhibit a simpler mechanical layout, employing only a pair of motors. This streamlined arrangement can lead to decreased weight, fewer mobile components, and potentially diminished maintenance needs. Furthermore, co-axial propellers tend to boast heightened efficiency with regards to power consumption and flight duration. In a contra-rotating rotor pair, the second rotor encounters not only the average swirling airflow generated by its preceding rotor (which it's specifically designed for, and which can enhance its performance), but also the variations in pressure and disturbances created by each blade. Contra-rotating propellers can achieve greater efficiency compared to a single propeller because they align and reduce the tangential component of the airflow, resulting in a more streamlined propwash. Additionally, for extremely powerful engines, these propellers have the added benefit of being capable of handling significantly higher levels of power Whenever a blade traverses one of these disturbances, the stagnation pressure at its front edge drops significantly and subsequently rises again This invention relates to structural arrangements whereby airplane propellers or the like are mounted co-axially with respect to the propeller shaft and in driven relation thereto, and the primary object of the invention is to provide simplified and more eilicient arrangements of this model for two or more co-axial propellers, turning in different directions.
The propeller (2d) within the Coaxial propeller assembly (3) is affixed to the lower hub assembly (2f), as depicted in Figure 2. The second propeller (2d) within the coaxial propeller assembly (3) is installed on the upper hub assembly (2b), as illustrated in Figure (3). The lower hub fairing (2f) is placed inside the inner race of the hub assembly, as depicted in Figure(2). The lower hub fairing (2f) is positioned within the inner race of the hub assembly, as shown in Figure (2). The lower hub fairing (2f) is introduced into the inner race of the hub assembly, as depicted in Figure (2). The upper propeller assembly in Figure (3) has the top hub fairing (2b) positioned on it. Figure (3) illustrates the comprehensive assembly of all sub-assemblies (1 and 2) within the coaxial propeller (3) for the morphing wing UAV.
The motor mounts are affixed to both the upper hub assembly (2e) and the lower hub assembly (2c) of the coaxial propeller for the morphing wing, as shown in Figure (3). According to claim 1 and as depicted in Figure (1), the coaxial propeller exhibits a superior thrust-to-weight ratio in comparison to the conventional single rotor propeller, as demonstrated in Figure (3). As outlined in claim 1, Figures (1) and (2) are utilized for the attachment of propellers to the motor shafts. As indicated in claim 1, Figures (1) and (3) showcase the assembly of the coaxial propeller assembly. In accordance with claim 1, the hub assembly securely fastens the propellers to the shaft, as illustrated in Figure (3). In alignment with claim 1, Figure (2) provides increased rigidity to the propeller assembly.

The opposing rotations of the propellers also contribute to minimizing the overall acoustic output generated by the UAV.The propeller is held in-between the inner and outer hub which intern attached to the casing of the frame. It will improve the structural rigidity and reduce noise due to vibrations of the propeller. The upper and lower propellers may experience different loading conditions due to aerodynamics. These loads are transmitted to the engine mount to the fuselage. The fairing of the assembly is intended to provide sufficient strength to the assembly and firmly hold the propeller in its hub. Similarly, lower or rear propeller also firmly fixed to the frame and provide rigidity of structure. The structural arrangement of coaxial propeller specified in the design can used for fixed wing unmanned aerial vehicles and drones.
3 Claims and 3 Figures , Claims:The scope of the invention is defined by the following claims:
Claims:
1. A CO-AXIAL PROPELLER FOR Morphing wing UAV comprising
(a) The propeller(2d) in Coaxial propeller assembly(3) is mounted on lower hub assembly(2f) figure(2)
(b) The second propeller(2d) in Coaxial propeller assembly(3) is mounted on mounted on upper hub assembly (2b) figure(2)
(c) The lower hub fairing(2f) is inserted into the inner race of the hub assembly figure( 2)
(d) The top hub fairing (2b) is placed on the upper propeller assembly in figure(3).
(e) The complete assembly of all sub assemblies(1,2 )in coaxial propeller(3) for morphing wing Uav.
(f) The motors mounts are attached to the upper hub assembly(2e) and Lower hub assembly(2c) of co-axial propeller for the morphing wing.
2. As per the claim 1, a coaxial propeller provides better thrust to weight ratio compared to the conventional conventional single rotor propeller
3. As per the claim1, the hub assembly holds the propellers filmy to the shaft and facilitates enhanced rigidity to the propeller assembly