Rotor Blade Damping Assembly Using Centrifugal Rolling Elements
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Solution Overview
Problem
Existing rotor assemblies face challenges in reducing vibration of rotor blades at natural frequencies corresponding to rotational speeds, particularly due to limitations in existing designs that fail to effectively dampen vibrations at these frequencies.
Innovation Solution
The implementation of U-shaped plate springs and rolling elements that interact with the rotor blades, where the rolling elements are pressed against a curved surface by centrifugal force, allowing them to roll and dampen vibrations at specific harmonic frequencies, and by making the integer-multiple orders of excitation harmonics of different rolling elements distinct, effectively reducing vibrations across various rotational speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an adjustment member is interposed between the platform and damper member to adjust the contact angle, then the flexibility of design is improved, but the vibration at natural frequency corresponding to rotational speed cannot be sufficiently reduced
Solution Approach 1:
The invention changes the geometric parameters of the damper member by providing both an inclined surface and a curved surface with different curvature radii. This allows adjustment of the contact angle between the damper member and rotor blade, enabling the system to effectively dampen vibrations at natural frequencies while maintaining design flexibility.
Solution Approach 2:
The damper member is segmented into multiple functional surfaces: an inclined surface for general vibration damping and a curved surface with specific curvature radius for targeting natural frequency vibrations. This segmentation allows each surface to address specific vibration characteristics, resolving the contradiction between design flexibility and vibration reduction effectiveness.
2Device complexity
If a single damper member configuration is used, then the device complexity is reduced, but the ability to dampen vibrations at different excitation harmonics is limited
Solution Approach 1:
The damper member is designed with multi-functionality by incorporating both an inclined surface and a curved surface with adjustable contact angles. This single component can address multiple excitation harmonics (different integer-multiple orders) simultaneously, providing universal vibration damping capability without increasing device complexity.
Solution Approach 2:
The curved surface of the damper member has a curvature radius that can be adjusted to change the contact angle dynamically. This allows the damper member to adapt to different rotational speeds and excitation harmonics, effectively damping vibrations across a range of operating conditions while maintaining a relatively simple device structure.
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
This solution significantly reduces rotor blade vibrations at natural frequencies corresponding to rotational speeds by utilizing the frictional and centrifugal forces, enhancing the damping effect and improving the flexibility and reliability of the rotor assembly design.
Implementation Method 1
the rolling element rolls on the curved surface
Implementation Method 2
the rolling element is pressed against the curved surface facing inward in the radial direction of the rotor disc due to the action of the centrifugal force
Implementation Method 3
frictional force acts between the U-shaped plate spring and the rotor blade to damp the vibration occurring in the rotor blade
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3B
AI summary
A rotor assembly includes: a rotor disc; a plurality of rotor blades fixed to the rotor disc and extending radially outward in a radial direction of the rotor disc; and at least one rolling element configured to roll on a curved surface facing inward in the radial direction of the rotor disc.