Rail Wheel Damper Segments With Preloaded Viscoelastic Contact
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Solution Overview
Problem
Existing vibration and noise dampers for rail vehicle wheels face inefficiencies due to poor vibration transmission, high costs, limited applicability, and reduced effectiveness over the wheel's lifespan, particularly when the rim is the dominant oscillating part, and challenges in ensuring optimal bracing and contact with the wheel.
Innovation Solution
A vibration and noise damper design featuring evenly fastened segments with a supporting part, a pushing part, and a damping part comprising a strain pliable metal or composite layer, viscoelastic layer, and possibly additional metal or composite layers, where the damping part is preloaded to maximize contact with the wheel rim using bolts, ensuring effective vibration transmission and damping through friction and viscoelastic deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If dampers are mounted to the rim part of the wheel using additional fastening elements, then the damper can be attached to the wheel, but the vibration transmission quality decreases and the efficacy of the damper decreases simultaneously
Solution Approach 1:
The supporting part of the damper is integrally formed with the damping part, eliminating the need for separate fastening elements. The damping part itself contacts the wheel rim directly, merging the attachment function and damping function into a single integrated structure, ensuring both strong attachment and effective vibration transmission.
Solution Approach 2:
The invention removes the intermediate fastening elements (spacers, bolts, rivets) from the contact path between the damper and wheel rim. By taking out these additional components, the vibration transmission path is simplified and direct contact is established between the damping part and wheel rim.
2Ease of manufacture
If dampers are divided into multiple parts with gaps between individual parts, then the damper can be mounted to the wheel, but the larger the gaps, the less the damper prevents the passage of sound waves
Solution Approach 1:
The damper is divided into multiple segments that can be mounted independently to the wheel, facilitating ease of installation and adaptation to different wheel sizes. Each segment maintains sufficient overlap and contact with the wheel rim to ensure continuous damping coverage.
Solution Approach 2:
The damping part uses composite material structures that provide both structural integrity for mounting and acoustic damping properties. The composite construction allows the segments to be rigid enough for secure attachment while maintaining sound-blocking capabilities.
3Loss of energy
If steel rings are used as shock absorbers inserted into circumferential grooves, then vibration level is reduced by dry friction, but it is technologically complicated to ensure optimal bracing of the rings
Solution Approach 1:
The supporting part is designed with flexible elements that can dynamically adapt to the wheel rim geometry and vibration conditions. This dynamic structure automatically adjusts the bracing and contact pressure, eliminating the need for complex pre-calculated rigid bracing systems.
Solution Approach 2:
The damper design allows for adjustable parameters such as contact pressure, contact area, and mounting position. These parameters can be optimized for different wheel types and vibration conditions without requiring complex structural changes, providing versatility across applications.
4Loss of energy
If resonantly tuned dampers are mounted on the wheel, then vibration levels are reduced for selected shapes of wheel vibrations, but the wheel wears during operation causing a change in its own frequency and detuning of the damper takes place
Solution Approach 1:
The damping part uses viscoelastic materials whose damping characteristics are not critically dependent on precise frequency tuning. The material properties provide broadband damping effectiveness that remains stable over time and across varying wheel frequencies, accommodating wear and frequency changes.
Solution Approach 2:
The damper design incorporates materials and structural features that provide effective damping across a wide frequency range rather than being optimized for a single resonant frequency. This broadband approach maintains effectiveness as wheel frequency changes due to wear and operational conditions.
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 solution provides stable and efficient vibration and noise damping with improved contact and reduced manufacturing costs, allowing for effective use across various wheel frequencies and extended lifespan without requiring complex groove production, ensuring consistent performance despite manufacturing tolerances.
Implementation Method 1
a damping part (4) which is placed between the pushing part (3) and the wheel rim (11)
Implementation Method 2
absorb mechanical energy produced by oscillation of a wheel, particularly by the shear deformation of the viscoelastic material
Implementation Method 3
The contact proportions between the dampers and the wheel including the geometry of individual parts of the dampers are determined on the base of measurements and calculations, so that the resulting damping effect on the wheel is maximized
Data Source
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AI summary
A vibration and noise damper for wheels of rail vehicles, to which wheels it is fastened with screws, pins, or rivets, which comprises of at least two segments formed by a supporting part (2) for gripping to the wheel (1), a pushing part (3) and a damping part (4), where the pushing part (3) is connected by means of bolts (9) with the supporting part (2) and is formed either by a single metal or composite element, or it is directly integral part of the damping part (4) and where the damping part (4) is formed in the direction away from the wheel (1) rim of a strain pliable metal or composite layer (4a), of a viscoelastic layer (4b), and possibly of other metal or composite layer (4c), wherein in compressed state the damping part (4) is placed between the pushing part (3) and the wheel (1) rim. Preferably, the supporting part (2) is formed of metal or composite material. Also preferable is the embodiment when thermally insulating pads (5) are arranged between the supporting part (2) and the wheel (1) and/or between the fastening material for attaching the supporting part (2) to the wheel (1) and the wheel (1). The viscoelastic layer (4b) in the damping part (4) can comprise glass fibres and/or ceramic fibres and can be provided with a set of holes (4d) and/or radial cuts (4e) of various shape, wherein their number, size and arrangement are different for individual designs of the dampers in relevance to their shape.