Hub-Mounted Active Vibration Control With Tolerance Ring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vibration control devices for rotating aircraft hubs are inefficient at multiple frequency levels, prone to thermal degradation due to material mismatches, and suffer from weight, size, and reliability issues, leading to reduced operational life and increased wear.
Innovation Solution
A hub-mounted active vibration control system with a tolerance ring to accommodate thermal expansion mismatches, coaxial ring motors to rotate imbalance masses, and an electrical unit for independent control of mass position, phase, and speed, combined with a de-icing distributor for thermal management and reduced wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional hub-mounted bifilar absorbers are used for vibration control, then vibration mitigation is achieved at one force frequency level, but the device is inefficient at multiple frequency levels and limited to single-frequency operation
Solution Approach 1:
The patent employs dynamic imbalance masses that can rotate independently at different speeds and phases, allowing the device to adapt to multiple vibration frequencies. The electrical unit independently controls the rotational position, phase, and speed of each imbalance mass, enabling the system to dynamically adjust to varying frequency conditions rather than being fixed at a single operating frequency.
Solution Approach 2:
The device is designed to simultaneously control multiple vibration frequencies using a single integrated system. Multiple imbalance masses operate at different frequencies and phases within the same device, allowing one universal device to perform the function of what would traditionally require multiple frequency-specific devices.
2Strength
If multiple different materials are incorporated in conventional vibration control devices, then structural requirements are met, but thermal degradation, fretting, and wear occur due to mismatches in thermal coefficients of expansion
Solution Approach 1:
The patent incorporates a tolerance ring specifically designed to accommodate dissimilar coefficients of thermal expansion between components made of dissimilar metals. This tolerance ring compensates for differential thermal expansion and contraction, preventing thermal degradation, fretting, and wear that would otherwise occur at material interfaces during temperature variations.
Solution Approach 2:
The tolerance ring acts as an intermediary component between dissimilar metal parts. It mediates the thermal expansion mismatch by providing a compliant interface that absorbs dimensional changes, thereby protecting the joint from thermal stress and maintaining reliability across temperature cycles.
3Reliability
If conventional vibration control devices are designed for robustness, then durability is improved, but weight and size increase
Solution Approach 1:
The patent utilizes composite material construction, particularly in the housing which can be made from composite or lightweight materials that maintain structural integrity while reducing weight. The integration of multiple functions into unified components (such as the housing serving both structural and thermal management roles) achieves robustness without excessive weight penalty.
Solution Approach 2:
The device integrates multiple components and functions into unified structures. The housing combines structural support, thermal management, and mounting functions. The electrical unit integrates control circuitry for multiple imbalance masses into a single compact package. This merging reduces overall device weight compared to having separate robust components for each function.
4Volume of moving object
If conventional vibration control devices are designed for compact dimensions, then space is saved, but heat dissipation and thermal management become problematic
Solution Approach 1:
The housing serves multiple functions simultaneously: it provides structural support, acts as a thermal management system through integrated heat dissipation features, and serves as a mounting structure. This multi-functionality allows compact dimensions without sacrificing thermal management capability, as the same structural components also handle heat dissipation.
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 system effectively cancels unwanted vibrations across multiple frequencies, extends operational life, reduces weight and size, and enhances thermal management and reliability, while integrating de-icing capabilities to prevent ice formation on aircraft blades.
Implementation Method 1
The housing comprises a tolerance ring configured to accommodate dissimilar coefficients of thermal expansion between components of dissimilar metals
Implementation Method 2
Imbalance masses rotating at different frequencies can substantially cancel unwanted vibration of the moving platform
Implementation Method 3
the combined forces of the imbalance masses substantially cancel unwanted vibration
Implementation Method 4
The HAVC device has a plurality of coaxial ring motors configured to rotate a plurality of imbalance masses
Implementation Method 5
The system includes a de-icing distributor provided over at least a portion of the mechanical unit. The de-icing distributor is configured to communicate instructions to one or more heating sources provided at one or more rotary blades
Data Source
AI summary
Hub-mounted active vibration control (HAVC) devices, systems, and related methods are provided. An HAVC device (100) includes a housing (206) having a tolerance ring (600) attached to a rotary hub (702). The tolerance ring can accommodate dissimilar coefficients of thermal expansion between dissimilar metals. The HAVC device can also include a plurality of coaxial ring motors (308A, 308B, 310A, 310B) configured to rotate a plurality of imbalance masses for controlling vibration. An HAVC system can further include a de-icing distributor (208) for communicating instructions to one or more heating sources (HS) provided at one or more rotary blades (802) of a vehicle or aircraft. A method of controlling vibratory loads occurring at a moving platform can include providing a moving platform, mounting a vibration control device to a portion of the moving platform, and rotating at least one pair of imbalance masses such that the combined forces of the masses substantially cancel unwanted vibration of the platform.