Modern machines and equipment continue to progress, providing better performance and efficiency. While this increase in equipment capabilities is great for productivity, it also leads to an increased need to effectively isolate vibration in order to keep the machines working at their best. If you find your equipment isn’t working properly, vibration may be the cause, but where do you begin?
Well, the first thing you want to do is gain a bit of insight on vibration isolation. We’re here to help you with just that! Let us walk you through some of the most important vibration isolation terms so you can better understand vibration isolation and how vibration isolators work to protect your equipment.
This is the physical property of a vibration isolator to remove energy from a vibrating system. Damping limits vibrations to an acceptable level and converts that mechanical energy into heat.
What isolation truly means is the decoupling of disturbance forces and vibration. This effect works from both the machine to the environment and the environment to the machine.
The natural frequency of an object is the frequency or rate at which it vibrates naturally when it is distrubed. Each vibration isolator has its own natural frequency that affects its efficiency at isolating vibration.
This is the vibration isolated mounting of a machine in order to reduce its pulse or sinusoidal vibration forces. Doing this helps protect the rest of your environment from the disturbing forces of the machine. This will protect adjacent machines, the building, and people from the effects of vibration.
Receiver isolation is used for vibration-sensitive machines that require protection from disturbing forces from the ground, for example, coordinate measuring machines.
Shock isolation is going to be commonly used with equipment that stamps, presses, or hammers. With this type of isolation, the dynamic disturbing pulses that consist of a high power peak over a short period of time are transformed into a longer lasting pulse that has smaller forces.
The effect of vibration isolation greatly depends on the ratio of disturbance frequency to the natural frequency of the isolator and its damping ratio. This disturbance frequency is going to differ based on the isolation being used. For source isolation, the disturbance frequency is the machine speed or stroke rates, while for receiver isolation it would be the disturbing ground vibrations. The biggest takeaway from this is that generally the lower the natural frequency of an isolator, the more efficient it will be at isolation vibration.
These isolators exhibit upon excitation of an amplification of the vibration amplitude that is in the range of the natural frequency of the isolator. This means that the resonance amplification is going to be dependent on the dampening characteristics of that specific isolator.
As opposed to passive vibration isolators, the resonance amplification in the natural frequency range of the active isolators is minimized and an optimum isolating effect is achieved with frequencies above the resonance range. These isolators generate a counter-force that is phase shifted by 180° through a suitable control.
