Due to the fragility of the equipment which is to be mounted and the level of urgency of the project, the AMC-Mecanocaucho technical department came up with a design which was robust, fail-safe and easy to install. This solution involved the use of the AMC BSB 150 and BSB 180 rubber-metal mounts.
In order to isolate the screen from the vibrations coming through the metal structure it was necessary to remove the rigid connection, replacing it with an elastic element. This was achieved by using the previously mentioned BSB rubber metal anti-vibration mounts. In order to confirm the performance of the system, a mathematical model of the whole system was created.
In this mathematical model the TV screen was added with the provided mass and center of gravity data, the moments of inertia of the whole system were calculated.
In this project, nine mounts have been considered. Three of them, the BSB 180 mounts, were placed under the screen and are responsible for supporting the majority of the weight. Due to the tall nature of the screen it was important to provide lateral stability to the system, six BSB 150 mounts were added horizontally to achieve this support.
Once the mathematical model was complete, excitations in the X Y and Z axis were added to visualize the isolation level that the mounts will provide. This is checked using the transmissibility curves which demonstrate the vibration levels of both sides of the rubber mounts.
The transmissibility curves make it is possible to check the isolation level that the anti-vibration mounts will provide at each frequency. The most suitable anti-vibration mounts are selected taking in to account the stiffness and damping properties, the required vibration isolation and stability is analysed.
The transmissibility curves obtained from the mathematical model show that the BSB 180 and BSB 150 rubber mounts will provide a good balance between isolation and stability.
In addition to this the calculation model shows that the natural frequencies of the system will be below the main excitation frequency which, in this case, has been considered to be 25Hz.
This installation achieves all of the key factors, a high level of robustness and stability whilst providing a flexible element with a low natural frequency, this ensures that there is a reduction in the vibrations that could affect the performance of the suspended element. BSB rubber metal mounts can be found in the catalogue of AMC-Mecanocaucho as a “Fail safe” product. This means that in case of a tensile force acting on the mounts that goes beyond the limit of the rubber element, the inner metal part will not allow the suspended element become detached.
With this calculation and the use of the BSB 150 and BSB 180 rubber metal mounts, a natural frequency of 15,8Hz was estimated for this project. In addition to this, good stability and robustness is achieved whilst providing a simple method of installation.
AMC MECANOCAUCHO manufactures anti vibration mounts and has a team of application engineers to help your installation needs so do not hesitate to contact our technical department if you require help on this topic.
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