Single-Blade Rotor Flyweight Balancing Horizontal Forces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotary wing aircraft with a single blade experience undesirable vibrations due to unbalanced horizontal components of lift and rotary drag forces, leading to excessive wear on bearings and rotor mast components, as existing solutions require complex mechanisms to compensate for these forces.
Innovation Solution
A balancing flyweight device is mounted on the rotor to counteract the resultant of the horizontal lift and drag forces, with its position and mass adjustable to oppose the interfering forces, using a mechanism that responds to the square of the blade's pitch angle to maintain balance regardless of load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a single blade rotor is used with a counterweight for centrifugal force balance, then the centrifugal force equilibrium is almost perfect, but the horizontal component of lift force and rotary drag force generate unwanted vibrations and increase wear on bearings
Solution Approach 1:
The patent introduces a second counterweight specifically designed to balance the horizontal component of lift force and rotary drag force. This counterweight rotates with the blade and is positioned to generate a centrifugal force that opposes the unwanted horizontal forces, thereby reducing vibrations and wear on bearings while maintaining the original centrifugal force equilibrium.
Solution Approach 2:
The balancing function is segmented into two independent counterweights: one for centrifugal force balance and another for horizontal force balance. This segmentation allows each counterweight to be optimized for its specific function, enabling precise control over different force components without interfering with the other balancing requirement.
2Object-generated harmful factors
If the position of the counterweight is adjusted to compensate for horizontal forces, then vibration compensation improves, but the mechanism becomes difficult to implement
Solution Approach 1:
The second counterweight is designed to automatically position itself based on the blade's pitch angle and rotation speed. The system uses the existing rotational motion and force fields to self-adjust the counterweight position, eliminating the need for complex external adjustment mechanisms while maintaining effective vibration compensation.
3Adaptability or versatility
If the flyweight position is adjusted based on the square of the pitch angle, then compensation accuracy improves across varying conditions, but the control mechanism complexity increases
Solution Approach 1:
The patent utilizes the relationship between the flyweight position and the square of the pitch angle to automatically adjust compensation. By designing the mechanical linkage or control system to follow this mathematical relationship, the system adapts to varying pitch angles and rotation speeds without requiring complex real-time calculations, maintaining accuracy across different operating conditions while limiting control complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The flyweight device effectively compensates over 90% of the interfering forces, reducing vibrations and wear on rotor components, while allowing for flexible operation across varying conditions and speeds, including takeoff, landing, and cruising phases.
Implementation Method 1
under the effect of the centrifugal force to which it is subjected while the rotary wing is rotating, generating a horizontal force that is applied to the rotary shaft of the motor and that opposes the above-mentioned resultant
Data Source
AI summary
A rotor for a rotary wing aircraft having a single blade with a longitudinal pitch axis and that is hinge mounted on the rotary shaft for rotating the rotor, the hinge being about an axis that is transversal relative to the rotary shaft, said rotary wing describing a cone when its pitch angle is not zero, the rotor possessing a balancing flyweight device for balancing the resultant of the horizontal component of the lift force and of the rotary drag force of the blade, the device being mounted to rotate with the rotary wing about its rotary shaft and, under the effect of the centrifugal force to which it is subjected while the rotary wing is rotating, generating a horizontal force that is applied to the rotary shaft of the motor and that opposes the above-mentioned resultant with a magnitude of that is a function of the position of the flyweight(s) of the balancing device relative to the rotary shaft of the rotor.