Standard_Parts_Catalogue

Page 1494 | 3.4 Installing, Lifting, Damping with Leveling Feet, Lifting Gear and Rubber Elements Terms Interference frequency [Hz]: is the frequency emanating from a machine, e.g. the machine main shaft speed [rpm]. Static load F [N]: is the load acting on each vibration-damping element (leveling foot). Degree of insulation [%]: is the measure for absorbing the interference frequency (dampening). Compression s [mm]: is the change in height of the damping element (spring excursion). Stiffness R [N/mm]: is the load which causes a damping element to be compressed by 1 mm (spring rate). GN 148 Leveling Feet Determining the Suitable Leveling Foot Determining the suitable leveling foot and the maximum degree of insulation First, the static load F for each leveling foot must be determined. For well arranged leveling feet and the resulting even distribution of the load F, the static load is calculated using the following equation: = Static load F [N] / per leveling foot Once the static load F has been calculated, select a leveling foot from the table. Please note that the static load F should be as close as possible to the static load capacity, but without exceeding it. The associated stiffness R of the selected leg is also shown in the table. The actual compression is then calculated using the equation below. = Actual compression s [mm] Starting from the actual compression s calculated, the maximum degree of insulation as factor of the interference frequency can now be read in the above chart. To optimise the maximum degree of insulation, change the number of feet such that the static load F of each leveling foot is as close as possible below a static load capacity value given in the table. This will increase the compression s which, in turn, improves the degree of insulation. In general, medium and high frequencies can be very well insulated with an adequate compression. Weight force of the machine [N] Number of leveling feet Static load F [N] / per leveling foot Stiffness R [N/mm]