Helicopter Landing Gear Bracket Pendulum Vibration Isolation
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Solution Overview
Problem
Helicopters experience ground resonance due to vibrations and resonance modes when landing on sloping surfaces, which can render them inoperable, and existing solutions require costly and cumbersome modifications to the landing gear and cabin.
Innovation Solution
A bracket system is introduced that connects the landing gear traverse to the helicopter cabin using a pendulum mechanism with clamping rings and pendulum bolts, allowing for rotational and longitudinal mobility, thereby detuning vibrations without altering the existing cabin or landing gear structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the landing gear and cabin are rigidly connected to prevent ground resonance, then vibration isolation is improved, but the structural complexity and weight increase
Solution Approach 1:
The patent applies a pendulum mechanism that allows dynamic movement between the cabin and landing gear. The pendulum arm with lower pendulum bolts enables controlled oscillation and energy dissipation, transforming the rigid connection into a dynamic system that adapts to vibration frequencies, thereby reducing ground resonance without increasing structural complexity
Solution Approach 2:
The pendulum mechanism acts as an intermediary element between the cabin and landing gear. It mediates the vibration transmission by providing a compliant connection that filters out harmful resonance frequencies while maintaining structural integrity, avoiding the need for complex vibration isolation systems
2Object-affected harmful factors
If the landing gear and cabin are rigidly connected to prevent ground resonance, then vibration isolation is improved, but the weight increases
Solution Approach 1:
The pendulum mechanism provides vibration isolation through dynamic movement rather than rigid structural reinforcement. By allowing controlled oscillation of the pendulum arm, the system dissipates vibration energy without requiring heavy damping materials or complex isolation systems, thereby maintaining lightweight construction
Solution Approach 2:
The pendulum serves as a lightweight intermediary that provides vibration filtering functionality. It replaces the need for heavy vibration isolation systems while effectively isolating the cabin from landing gear vibrations, achieving vibration protection with minimal weight addition
3Object-affected harmful factors
If existing landing gear modifications are implemented to prevent ground resonance, then vibration isolation is improved, but the manufacturing cost and complexity increase
Solution Approach 1:
The patent employs a pendulum mechanism that utilizes simple mechanical principles rather than complex active control systems. The lower pendulum bolts and pendulum bearings provide passive vibration isolation through gravity and inertial effects, making the system easier to manufacture and maintain compared to active damping systems
Solution Approach 2:
The pendulum mechanism serves as a simple intermediary device that can be integrated into existing landing gear configurations. It requires minimal modification to the original structure, using standard mechanical components that are easy to manufacture and install, thereby reducing manufacturing complexity and cost
4Object-affected harmful factors
If the pendulum mechanism allows longitudinal mobility, then vibration isolation is improved, but the stability during flight may be compromised
Solution Approach 1:
The pendulum mechanism provides dynamic stability by allowing controlled oscillation in the longitudinal direction while maintaining overall structural integrity. The lower pendulum bolts enable the cabin to move slightly with landing gear vibrations, dissipating energy while the pendulum's gravitational restoring force maintains positional stability during normal flight operations
Solution Approach 2:
The pendulum acts as a stabilizing intermediary that decouples vibration transmission from structural instability. It allows longitudinal mobility to filter vibrations while the pendulum's geometric configuration and gravitational forces ensure the cabin remains properly positioned relative to the landing gear during flight, preventing instability
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 effectively isolates oscillations between the cabin and landing gear, preventing ground resonance without the need for extensive modifications, is lightweight, compact, and cost-effective, maintaining the original landing gear qualities and avoiding the need for new certification.
Implementation Method 1
The bracket comprises a landing gear retainer fixed by clamping rings about the traverse coaxially to the longitudinal direction of the traverse. The landing gear retainer is adapted to be fixed to the preferably at least one cabin clamp mount by means of a pendulum and at least one upper and at least one lower pendulum bolts in at least one upper and at least one lower pendulum bearings of the pendulum.
Implementation Method 2
This solution effectively isolates oscillations between the cabin and landing gear, preventing ground resonance without the need for extensive modifications
Data Source
AI summary
A bracket for connecting a traverse of a landing gear to a cabin of a helicopter. A landing gear retainer is fixed around the traverse coaxially to the longitudinal direction of the traverse and at least one cabin clamp mount is fixed to the cabin. The landing gear retainer is in between the cabin and upper and lower pendulum bolts and upper and lower pendulum bearings. A pendulum is in longitudinal direction of the traverse hinged to the landing gear retainer. The invention is further related to an application of such brackets.