Leaf-Spring Tuned Mass Damper for Variable-Frequency Vibration
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Solution Overview
Problem
Existing tuned mass dampers struggle to provide effective damping over a wide frequency range without requiring frequent readjustment due to changing rotational speeds, particularly in systems like wind power plants, where they often cause increased structure-borne sound.
Innovation Solution
A tuned mass damper using stacked, pre-bent leaf-springs with adjustable stiffness, achieved through devices like piezo elements or bimetallic elements, allows for frequency adaptation by changing the leaf-spring assembly's stiffness in response to varying disturbance frequencies, minimizing mechanical adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional passive dampers with fixed stiffness are used, then the damper is simple in structure and easy to manufacture, but it cannot adapt to changing disturbance frequencies caused by varying rotational speeds
Solution Approach 1:
The patent applies the dynamics principle by making the leaf-spring stiffness adjustable rather than fixed. The leaf-spring assembly can change its stiffness parameter in response to varying disturbance frequencies, allowing the damper to adapt dynamically to different operating conditions while maintaining a relatively simple overall structure.
Solution Approach 2:
The patent implements parameter changes by modifying the stiffness parameter of the leaf-spring assembly. Through devices such as piezo elements or bimetallic elements, the stiffness of the leaf-springs can be adjusted to match changing disturbance frequencies, enabling frequency adaptation without fundamentally redesigning the damper structure.
2Adaptability or versatility
If the leaf-spring length is mechanically adjusted to change frequency, then the damping frequency can be adapted, but the device requires frequent readjustment and has mechanically moving parts that increase complexity and maintenance
Solution Approach 1:
The patent replaces mechanical adjustment systems with non-mechanical or minimally mechanical means. Instead of using mechanically moving parts to adjust leaf-spring length, the invention uses piezo elements or bimetallic elements that change stiffness through electrical or thermal actuation, eliminating the need for frequent mechanical readjustment and reducing maintenance requirements.
Solution Approach 2:
The damper system can automatically adjust its stiffness parameter in response to changing operating conditions without requiring manual intervention. The piezo or bimetallic elements respond autonomously to frequency changes, allowing the system to self-adjust and eliminating the need for frequent operator readjustment.
3Object-affected harmful factors
If elastomer-based passive dampers are used, then the damper works over a wide frequency range without readjustment, but it causes increased structure-borne sound when rotational speeds change frequently
Solution Approach 1:
The patent changes the stiffness parameter of the leaf-spring assembly to match varying disturbance frequencies. By adjusting the stiffness in real-time or near real-time, the damper maintains its effectiveness across different frequency ranges while reducing structure-borne sound, overcoming the limitation of fixed elastomer dampers that cannot adapt to frequency changes.
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 damper maintains optimal damping across a wide frequency range with minimal maintenance, adapting to changing speeds without the need for frequent readjustment, reducing vibrations and structure-borne sound effectively.
Implementation Method 1
a device, in particular a displacement device (5),(6),(14)-(18), or an electrical or thermal device with this function, such as a piezo element or a bimetallic element to change the predetermined stiffness of the leaf-spring assembly (2)
Implementation Method 2
a device, in particular a displacement device (5),(6),(14)-(18), or an electrical or thermal device with this function, such as a piezo element or a bimetallic element to change the predetermined stiffness of the leaf-spring assembly (2)
Implementation Method 3
one or more leaf-spring assemblies (2), consisting essentially of at least one, but preferably of two or more, in particular three, four, five, six or more, individual, stacked leaf-springs (2.1) of predetermined stiffness
Data Source
AI summary
The invention relates to a tuned mass damper or vibration damper which, with the aid of an assembly (2) of a plurality of stacked, specially shaped or bent leaf springs (2.1), can be adapted over a certain range to the disturbance frequencies acting on a component to be damped or of the vibration system to be damped, the position of the damper mass (1, 34) being changed essentially only slightly. The invention relates in particular to one- and two-dimensionally effective tuned mass dampers. The tuned mass dampers according to the invention are suitable in particular for installations, vehicles and machines that undergo frequent changes in rotational speed, resulting frequently in disturbance frequencies that become noticeable, in particular, in the form of structure-borne sound, or other vibrations.