Gear-Amplified Eddy Current Damper for Small-Amplitude Vibration
Solution Overview
Problem
Existing axial displacement dampers have low energy dissipation efficiency at small amplitudes and poor capability in consuming vibration and shock energy, affecting the safety of buildings and people.
Innovation Solution
An axial displacement amplified eddy current damper is designed, combining an axial displacement damper with an eddy current damper, utilizing an elliptical hollow body, gears, copper sheets, permanent magnets, and spherical steel balls to convert axial motion into rotational motion, generating eddy currents that amplify energy consumption through gear ratios and magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an axial displacement damper is used, then the building is protected from vibration damage, but the energy dissipation efficiency is low at small amplitudes
Solution Approach 1:
The patent replaces traditional mechanical friction-based damping with electromagnetic eddy current damping. The copper sheets moving through magnetic fields generate eddy currents that produce damping forces without mechanical contact, eliminating friction losses and achieving high energy dissipation efficiency across all amplitude ranges while maintaining reliable vibration protection.
Solution Approach 2:
The patent changes the damping mechanism from mechanical friction to electromagnetic interaction by introducing copper sheets and magnetic fields. This parameter change enables the system to dissipate energy efficiently at small amplitudes through eddy current generation, while the gear amplification mechanism ensures adequate damping force at larger amplitudes, resolving the contradiction between reliability and energy efficiency.
2Loss of energy
If the damping force is increased, then the vibration energy consumption capability is improved, but the device complexity increases
Solution Approach 1:
The patent converts linear axial displacement into rotational motion through gear mechanisms. The slide bar's linear movement drives gear a, which rotates gear b and subsequently gear c, converting one-dimensional linear motion into rotational motion. This dimensional transformation enables the copper sheets to rotate through magnetic fields, generating eddy currents that dissipate vibration energy efficiently without requiring complex direct linear damping structures.
Solution Approach 2:
The patent introduces gear mechanisms as intermediary elements between the slide bar and copper sheets. The gears act as mediators that amplify the displacement and convert motion type, enabling the copper sheets to achieve sufficient rotational speed and angle for effective eddy current generation while keeping the overall structure manageable through modular gear design.
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 significantly increases energy consumption efficiency, allows adjustable damping parameters, provides a stable vibration reduction effect without external energy, and minimizes magnetic leakage, enhancing safety and reducing damage from vibrations.
Implementation Method 1
the relative motion of the copper sheets and the magnetic field causes a motional electromotive force in the copper sheets, and the electric charge moves to form eddy currents
Implementation Method 2
the copper sheets are subjected to a force that inhibits the motion thereof. This is because the relative motion of the copper sheets and the magnetic field causes a motional electromotive force in the copper sheets
Implementation Method 3
These eddy currents are subjected to a lorentz force under the action of the magnetic field, and the direction is always opposite to the direction of motion of the copper sheets
Implementation Method 4
the rotation angle of the copper sheets can be amplified; the rotation angle is (d/Ra)×(Rb/Rc); and the amplification is Rb/Rc, that is, the larger the radius ratio of the gear b to the gear c is, the higher the energy consumption efficiency is
Implementation Method 5
The permanent magnets 9 are located on both sides of the copper sheets 8
Implementation Method 6
the ball a10, the ball b11 and the balls c12 are spherical steel balls
Data Source
AI summary
An axial displacement amplified eddy current damper is disclosed. The axial movement of a slide bar is converted into the rotation of copper sheets and generates eddy current for energy consumption. The copper sheets are rotated and amplified by adjusting the sizes of gears. The short displacement of the slide bar can cause a large angle rotation of the copper sheets, so that energy consumption efficiency is high. The damping parameter can be adjusted by adjusting the magnetic field strength of permanent magnets, the thickness of the copper sheets and the distance from the copper sheets to the permanent magnets. The permanent magnets are adopted to provide continuous magnetic field sources, without external energy, thereby generating long-term and stable vibration reduction effect.