GN 148 Levelling feet with vibration damping element


  • RoHS

Description

Specification

Types

  • Type A: with two-hole flange (d1 = 60 / 90 / 113)
  • Type B: with four-hole flange (d1 = 113 / 126)

Identification no.

  • No. 1: without tear-off lock
  • No. 2: with tear-off lock
Vibration damping element
Natural rubber (NR)
vulcanized
temperature resistant up to 80 °C
Hardness [Shore A ±5 °]
soft* 43
medium 57
hard* 68
* not available from stock, requires a minimum order quantity
Sheet metal
zinc plated, blue passivated
Threaded insert
Steel
zinc plated, blue passivated

Information

Levelling feet GN 148 are designed for setting up heavy machinery and units with insulation against vibrations.
This has a positive impact on the lifetime of machines and additionally reduces the noise pollution.
The structure is such that horizontal forces are also absorbed. The design with tear-off lock (Type 2) protects the levelling feet from destruction caused by tear-off under excessive tension loads.
The details relating to the load bearing capacity are non-binding recommended values and rule out any liability. They constitute no general warranty of quality and condition. The user must determine from case to case whether a product is suitable for the intended use.

Accessory

Technical information (Terms)

F1 = static load in vertical direction (pressure)
F2 = static load in horizontal direction (lateral thrust)
s1 = Compression in vertical direction (spring excursion) under load thorugh F1
s2 = Compression in vertical direction (spring excursion) under load through F2
Stiffness R:
is the load which causes the damping elements to be compressed by 1 mm (spring rate)
Equation for calculating the stiffness: R = F / S
The table below gives details on the maximum static load F, the maximum rated compression and the resulting stiffness R.
The method shown and the values given below allow the maximum degree of insulation of the vibration to be determined as a factor of the interfence frequency.
d1Hardness in Shoremax. static load F1 in NStiffness R1 in N/mmmax. compression s1, in mmmax. static load F2 in NStiffness R2 in N/mmMax. Compression s2 in mm
6043*11003403.223007703
605717505503.2340011303
6068*28009303400013303
9043*15004303.530007504
905728008003.5500013303.75
9068*450012903.5700018703.75
11343*350010003.5450012903.5
11357650018603.5750021403.5
11368*1000028603.51100031403.5
12643*750021403.5900025703.5
126571250035703.51500042903.5
12668*1900053403.52250064303.5

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 (levelling foot).
Degree of insulation [%]:
is the measure for absorbing the interference frequency (damping).
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).

Determining the suitable levelling foot and the maximum degree of insulation

First, the static load F for each levelling foot must be determined. For well arranged levelling feet and the resulting even distribution of the load F, the static load is calculated using the following equation:
Weight force of the machine [N] / Number of levelling feet = Static load F [N] / per levelling foot
Once the static load F has been calculated, select a levelling 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.
Static load F[N] / per levelling foot / Stiffness R [N/mm] = 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 levelling 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.

Example of application

Levelling feet with vibration damping element  GN 148
GN 148
Filter
Description d1 d2 d3 d4 d5 h s b l1 l2 m1 m2 Weight
GN 148-60-M10-A-1-43 60 M 10 78 9 - 30 2 78 128 - 110 - 238
GN 148-60-M10-A-2-43 60 M 10 78 9 - 30 2 78 128 - 110 - 282
GN 148-60-M10-A-1-57 60 M 10 78 9 - 30 2 78 128 - 110 - 250
GN 148-60-M10-A-2-57 60 M 10 78 9 - 30 2 78 128 - 110 - 279
GN 148-60-M10-A-1-68 60 M 10 78 9 - 30 2 78 128 - 110 - 245
GN 148-60-M10-A-2-68 60 M 10 78 9 - 30 2 78 128 - 110 - 280
GN 148-90-M12-A-1-43 90 M 12 106 13 - 39 3 110 170 - 140 - 717
GN 148-90-M12-A-2-43 90 M 12 106 13 - 39 3 110 170 - 140 - 806
GN 148-90-M12-A-1-57 90 M 12 106 13 - 39 3 110 170 - 140 - 725
GN 148-90-M12-A-2-57 90 M 12 106 13 - 39 3 110 170 - 140 - 809
GN 148-90-M12-A-1-68 90 M 12 106 13 - 39 3 110 170 - 140 - 730
GN 148-90-M12-A-2-68 90 M 12 106 13 - 39 3 110 170 - 140 - 815
GN 148-113-M16-A-1-43 113 M 16 150 12.5 - 52 4 150 216 - 184 - 1643
GN 148-113-M16-A-2-43 113 M 16 150 12.5 - 52 4 150 216 - 184 - 1854
GN 148-113-M16-A-1-57 113 M 16 150 12.5 - 52 4 150 216 - 184 - 1641
GN 148-113-M16-A-2-57 113 M 16 150 12.5 - 52 4 150 216 - 184 - 1900
GN 148-113-M16-A-1-68 113 M 16 150 12.5 - 52 4 150 216 - 184 - 1713
GN 148-113-M16-A-2-68 113 M 16 150 12.5 - 52 4 150 216 - 184 - 1975
GN 148-113-M16-B-1-43 113 M 16 150 - 12.5 52 4 - - 168 - 132 1878
GN 148-113-M16-B-2-43 113 M 16 150 - 12.5 52 4 - - 168 - 132 2040
GN 148-113-M16-B-1-57 113 M 16 150 - 12.5 52 4 - - 168 - 132 1830
GN 148-113-M16-B-2-57 113 M 16 150 - 12.5 52 4 - - 168 - 132 2019
GN 148-113-M16-B-1-68 113 M 16 150 - 12.5 52 4 - - 168 - 132 1870
GN 148-113-M16-B-2-68 113 M 16 150 - 12.5 52 4 - - 168 - 132 2000
GN 148-126-M20-B-1-43 126 M 20 177 - 13 63 4 - - 184 - 150 2613
GN 148-126-M20-B-2-43 126 M 20 177 - 13 63 4 - - 184 - 150 2890
GN 148-126-M20-B-1-57 126 M 20 177 - 13 63 4 - - 184 - 150 2623
GN 148-126-M20-B-2-57 126 M 20 177 - 13 63 4 - - 184 - 150 2916
GN 148-126-M20-B-1-68 126 M 20 177 - 13 63 4 - - 184 - 150 2680
GN 148-126-M20-B-2-68 126 M 20 177 - 13 63 4 - - 184 - 150 2800