Airmount® isolator Selection Procedure
Refer to the selection guide on this page for Airmount isolator capabilities.
1. LOAD CAPACITY
Select one or two Airmount isolators that can support the load at each mounting point. It is normally best to design for pressures in the 4 to 6 BAR range. Consider only the 1M1A and the single and double convoluted types at first. Please notice that in the range of 1 to 285 kN you will, in most cases, find both a single and double convoluted style part which will support the load.
2. DETERMINE ISOLATION EFFECTIVENESS
Locate the forced frequency on the vertical axis of the chart on page 9. Locate the natural frequencies of the parts selected above and find these values on the horizontal axis of the Isolation Chart. At the intersection of the forced frequency and natural frequency lines you will be able to determine the approximate percentage of isolation by comparing this point with the diagonal lines representing these percentages.
3. DETERMINE DESIGN HEIGHT
The Airmount isolator SHOULD BE USED AT THE DESIGN HEIGHT GIVEN. The double convoluted part is used at a design height somewhat higher than its single convolution equivalent. Make sure that the design height falls within the height restricͭtions. Also, the double convoluted part will show a higher percentage of isolation (less transmitted vibration) than the single convoluted air spring. The reason for this is that the double convoluted part has a greater internal volume of air than the single convoluted version of the same size. At disturbing frequencies in the 7 to 13 Hz range, the double convoluted part is a significantly better vibration isolator than the single convoluted part. At disturbing frequencies of 13 to 25 Hz the gap closes considerably. At frequencies of 25 Hz and above, the difference is negligible.
4. DETERMINE EXACT INTERNAL PRESSURE AND ISOLATION
The chances are that your specific vibration problem does not fall neatly into the load and disturbing frequency criteria as presented in the selection guide. Therefore, once a preliminary part selection has been made, turn to the individual data page in the Engineering Manual and Design Guide for that part in order to determine the specific internal pressure required and the percentage of isolation attainable.
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*Do not inflate above 5 BAR. tExcept for 1X84D-1 and 1M1A.
** When using the rolled plate end closure option, add 17.5 mm to heights shown.