Belleville Spring Elastomer Vibroisolator for Nonlinear Suspension
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Solution Overview
Problem
Existing vibroisolating devices in motor vehicles fail to provide a nonlinear force vs. displacement characteristic that is symmetrical around a nonzero equilibrium point, leading to inadequate vibration isolation for both low and high amplitude vibrations, especially in active suspension systems where preload shifts the equilibrium position, causing discomforting forces during small displacements.
Innovation Solution
Incorporating a preloaded Belleville spring within the elastomeric core of the vibroisolating device, which alters its isotropy and allows for adjustable equilibrium positioning, enabling high and low stiffness responses for high and low amplitude vibrations respectively, by embedding the spring within the core and using a stiff support to connect displaceable objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a conventional elastomeric vibroisolating device is used, then it provides low stiffness for small amplitude vibrations, but it cannot provide symmetrical nonlinear force-displacement characteristic around a nonzero equilibrium point
Solution Approach 1:
The patent combines an elastomeric core with a Belleville spring to create a composite vibroisolating device. The elastomeric material provides low stiffness for small vibrations, while the Belleville spring introduces nonlinearity and enables symmetrical force-displacement characteristics around a nonzero equilibrium point, resolving the contradiction between material simplicity and performance complexity.
Solution Approach 2:
The Belleville spring changes the force-displacement parameter characteristics of the device. By preloading the spring, the device achieves a nonlinear force-displacement curve that is symmetrical around a nonzero equilibrium position, allowing effective vibration isolation for both compression and extension movements unlike conventional linear elastomeric devices.
2Adaptability or versatility
If the vibroisolating device is preloaded to shift equilibrium position, then it compensates for predefined preload in active suspension, but it generates discomforting forces during small displacements
Solution Approach 1:
The combination of elastomeric material and Belleville spring creates a composite structure where the elastomer absorbs small amplitude vibrations through its inherent damping properties, while the Belleville spring handles larger displacements and maintains the shifted equilibrium position, preventing discomforting forces.
Solution Approach 2:
Different parts of the device serve different functions: the elastomeric core handles small amplitude vibrations locally with its damping characteristics, while the Belleville spring manages the overall equilibrium positioning and large displacement responses, creating localized specialized functionality that eliminates harmful forces.
3Force
If high stiffness is provided for high stroke vibrations, then mutual displacements are transmitted effectively, but small amplitude vibrations around equilibrium are not isolated efficiently
Solution Approach 1:
The Belleville spring introduces nonlinear parameter changes in the force-displacement relationship. At small displacements around the shifted equilibrium, the spring operates in a region providing low stiffness for effective isolation, while at large strokes, the spring's geometric nonlinearity increases stiffness to transmit mutual displacements effectively, resolving the stiffness contradiction.
Solution Approach 2:
The device transitions from a static linear stiffness characteristic to a dynamic nonlinear stiffness characteristic. The effective stiffness changes dynamically with displacement amplitude: low stiffness for small vibrations enables isolation, while high stiffness for large strokes enables effective force transmission, achieving both requirements through dynamic adaptation.
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 effectively compensates for predefined preload in active suspension systems, providing improved vibration isolation by shifting the equilibrium position and altering the stress-strain characteristics, resulting in enhanced comfort and control during various driving conditions.
Implementation Method 1
at least one Belleville spring disposed on the vibration transmitting path between said first and said second displaceable objects
Implementation Method 2
a substantially elastomeric core configured to be connected with a first displaceable object
Implementation Method 3
substantially elastomeric core configured to be connected with a first displaceable object
Implementation Method 4
said at least one Belleville spring is preloaded while said vibroisolating device is in its equilibrium position
Data Source
AI summary
A vibroisolating device (1) comprises a substantially elastomeric core (2) configured to be connected with a first displaceable object (3) and provide with an opening (21) configured to be connected with a second displaceable object (4). In order to obtain a nonlinear force vs. displacement characteristic of the device, substantially symmetrical around a certain and adjustable nonzero displacement value, the device (1) comprises at least one Belleville spring (5) disposed on the vibration transmitting path between said first displaceable object (3) and said second displaceable object (4), which is at least partially embedded in the volume of said substantially elastomeric core (2) and surrounds said opening (21). In particular the spring (5) is preloaded while said vibroisolating device (1) is in vibrations equilibrium position. The invention also relates to a motor vehicle suspension, in particular an adjustable active suspension system, comprising such a vibroisolating device.