Vibration-damping elements

Transcription

1 Vibration-damping elements

2 DVA 2 Base - DVA: glossy zinc-plated steel. - DVA-SST: AISI 304 stainless steel. Vibration-damping body Natural rubber NR, hardness 55±5 Shore A, black colour. Standard executions - DVA.1: glossy zinc-plated steel threaded studs. - DVA.1-SST: AISI 304 stainless steel threaded studs. - DVA.2: thredead stud and boss in glossy zinc-plated steel, threaded blind hole. - DVA.2-SST: thredead stud and boss in AISI 304 stainless steel, threaded blind hole. - DVA.3: glossy zinc-plated steel bosses, threaded blind hole. - DVA.3-SST: AISI 304 stainless steel bosses, threaded blind hole. - DVA.4: glossy zinc-plated steel threaded stud. - DVA.4-SST: AISI 304 stainless steel threaded stud. - DVA.5: glossy zinc-plated steel boss, threaded blind hole. - DVA.5-SST: AISI 304 stainless steel boss, threaded blind hole. - DVA.6: glossy zinc-plated steel threaded stud. - DVA.6-SST: AISI 304 stainless steel threaded stud. - DVA.7: glossy zinc-plated steel boss, threaded blind hole. - DVA.7-SST: AISI 304 stainless steel boss, threaded blind hole. Special executions on request - Natural rubber NR, hardness 40±5 Shore A. - Natural rubber NR, hardness 70±5 Shore A. Features and applications Elesa+Ganter vibration-damping elements have been designed to damp vibrations, shocks and noises produced by moving bodies or vibrating masses which can cause: - malfunctioning and reduction of the machine lifespan and/or of the adjacent ones - noise - damage to men s health. Technical data and guidelines for the choise 1) Basic data required: - disturbing frequency: the frequency of the disturbing vibration produced by a on-duty machine. In general, it is obtained by the number of rotations of the engine [Hz=r.p.m./60]; - the load applied to every single vibration-damping element [N]; - the isolation degree required [%]; - the deflection value of the vibration-damping element under a given load [mm]; - the rigidity [N/mm], that is to say the load that applied to the vibration-damping element produces a deflection of 1.0 mm. For DVA.6 and DVA.7 the non-linear progress of the rigidity as reported in the graphs. 2) How to choose the vibration-damping element: - with reference to the diagram for checking the isolation degree, intersect the disturbing frequency value with the isolation degree required (each isolation degree corresponds to a line in the diagram) and define the deflection [in mm]; - divide the load applied onto the vibration-damping element by the deflection value to obtain the required rigidity of the vibration-damping element; - compare the rigidity obtained with the rigidity shown in the table and choose the vibration-damping element which presents the nearest value (lower) to the calculated one. 3) Check: - the deflection of the vibration-damping element chosen can be obtained in the graphs (DVA.6-DVA.7) on the basis of the load; - intersect the disturbing frequency value with the vibration-damping element deflection value in the diagram to obtain the isolation degree offered by the vibration-damping element chosen; - compare the obtained value with the isolation degree required. 4) Example: Conditions of use: - disturbing frequency= 50 Hz (3,000 r.p.m.); - load applied on each vibration-damping element 120 N; - 90% isolation required; - diagram shows that with a 50 Hz disturbing frequency and an isolation degree of 90%, the deflection obtained is 1.0 mm; - divide the load applied by the deflection obtained to define the rigidity required, which is 120/1.0 = 120 N/mm; - compare the rigidity value obtained (120 N/mm) with the values reported in the table; - the values reported in table, for type DVA.1, show that the vibration-damping element which should be used is DVA M

3 3

4 DVA.1 4 Standard Elements Main dimensions Max load Max deflection Stiffness DVA.1 DVA.1-SST Code Description Code Description D L d l [N] [mm] [N/mm] g DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M

5 DVA.2 5 Standard Elements DVA.2 DVA.2-SST Main dimensions Max load Max deflection Stiffness Code Description Code Description D L d l h [N] [mm] [N/mm] g DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M

6 DVA.3 6 Standard Elements DVA.3 DVA.3-SST Main dimensions Max load Max deflection Stiffness Code Description Code Description D L d h [N] [mm] [N/mm] g DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M

7 DVA.4 Standard Elements DVA.4 DVA.4-SST Main dimensions Max load Max deflection Stiffness Code Description Code Description D L d l [N] [mm] [N/mm] g DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M

8 DVA.5 8 Standard Elements DVA.5 DVA.5-SST Main dimensions Max load Max deflection Stiffness Code Description Code Description D L d h [N] [mm] [N/mm] g DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M

9 DVA.6 DVA.7 9 Standard Elements DVA.6 DVA.6-SST Main dimensions Max load Max deflection Code Description Code Description D L d l [N] [mm] g DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M Standard Elements DVA.7 DVA.7-SST Main dimensions Max load Max deflection Code Description Code Description D L d h [N] [mm] g DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M DVA M DVA SST-M M

10 LW.A Vibration-damping levelling elements 10 Base Zinc-plated steel. Vibration-damping disk Natural rubber NR, hardness 80 Shore A, black colour, matte finish. Levelling plate Zinc-plated steel. Packing ring OR in NBR synthetic rubber. Threaded stem Zinc-plated steel, supplied not assembled. Nut and washer Zinc-plated steel. Assembly instructions - Put the base of the vibration-damping element under the machine and insert the stem through the hole (not tapped) in the frame of the machine (fig.1). - Turn the square end of the stem to take the levelling plate in contact with the machine thus obtaining the levelling required. Then lock with nut and washer (fig.2). Features and applications ELESA vibration-damping levelling elements have been designed to damp vibrations, shocks and noises produced by moving bodies or non-balanced vibrating masses of equipment and machines which can cause: - malfunctioning and reduction of the machine lifespan and/or of the adjacent ones - damage at men s health - noise. Standard Elements Main dimensions Threaded stem Max load Max deflection Stiffness Code Description D D1 L L1 min L1 max d2 d s [N] [mm] [N/mm] g LW.A-80-M12x1.25x M12x1.25 8x LW.A-120-M16x1.5x M16x1.5 9x LW.A-160-M20x1.5x M20x1.5 12x LW.A-200-M20x1.5x M20x1.5 12x

11 Technical data and guidelines for the choice 1) Basic data required: - disturbing frequency: the frequency of the disturbing vibration produced by a on-duty machine. In general, it coincides with the number of rotations of the engine [rpm] - the static load applied to every single vibration-damping element [N] - the isolation degree required [%] - damping disk deflection value [mm] under a given load - the stiffness, that is to say the load that applied to the vibration-damping element, produces a deflection of 1mm [N/mm]. 2) How to choose the vibration-damping element: - with reference to the nomograph (graphic 1), intersect the disturbing frequency value with the isolation degree required (each isolation degree corresponds to a line on the nomograph) and define the deflection (static deflection mm) - divide the load applied onto the vibration-damping element by the deflection value to obtain the required rigidity of the vibration-damping element - compare the rigidity obtained with the rigidity shown in the table and choose the vibration-damping element which presents the nearest value (lower) to the calculated one. 3) Check the values obtained: - the deflection of the vibration-damping element chosen can be obtained in graphic 2 on the basis of the static load. - intersect the disturbing frequency value with the vibration-damping element deflection value in the nomograph (graphic 1) to obtain the isolation degree offered by the vibration-damping element chosen. - compare the obtained value with the isolation degree required. 4) Example: A 80% isolation degree is required. Conditions of use: - disturbing frequency = 3,000 rpm; - load applied to every levelling element = 4,000 N. - Graphic 1 shows that with a 3,000 rpm disturbing frequency and an isolation degree of 80%, the deflection obtained is 0.6 mm. - Divide the load applied by the deflection obtained to define the rigidity required, which is 4,000/0.6= 6,666 N/mm. - Compare the rigidity value obtained (6,666 N/mm) with the values reported in the table. This value is within the rigidity value reported in the table for LW.A-120 (4,000 N/mm) and LW.A-160 (9,000 N/mm). Choose the vibration-damping element with the lower value that is LW.A-120. For a further check: - graphic 2 shows that LW.A-120 (4,000 N/mm) deflection is 1mm. - by intersecting the deflection value with the disturbing frequency of 3,000 rpm in the nomograph, the isolation degree obtained is 90%. This value is even greater than the required one; your choice has prooved correct. 11

12 GN 148 Levelling feet 12 Vibration-damping feet Natural rubber NR, hardness 57 ±5 Shore A, black colour. Sheet metal Zinc plated steel, blue passivated. Threaded insert Zinc plated steel, blue passivated. Standard executions available - Type A: with two hole fl ange (d1 = 60 / 90 / 113). - Type B: with four-hole fl ange (d1 = 113 / 126). Version - Identifi ctation no. 1: without tear-off lock. - Identifi ctation no. 2: with tear-off lock. Accessories on request Rubber pads GN (see page 14). Special executions on request - Natural rubber NR, hardness 43 ±5 Shore A. - Natural rubber NR, hardness 68 ±5 Shore A. Features and applications Levelling feet GN 148 are designed for setting up heavy machinery and units with insulationagainst 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. Standard Elements Main dimensions Description d1 d2 d3 d4 d5 h s b l1 l2 m1 m2 g GN M10-A M GN M10-A M GN M12-A M GN M12-A M GN M16-A M GN M16-A M GN M16-B M GN M16-B M GN M20-B M GN M20-B M

13 13 Technical data F1 = static load in vertical direction (pressure) F2 = static load in horizontal direction (lateral thrust) s1 = Compression in vertical direction (spring excursion under load through 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) F Equation for calculating the stiffness: R = s The table below gives details on the maximum static load F, the maximum rated compression and the resulting stiffness R. The method shown on page 14 and the values given below allow the maximum degree of insulation of the vibration to be determined as factor of the interference frequency. d1 Hardness in Shore max. static load F1 in N Stiffness R1 in N/mm max. compression s1 in mm max. static load F2 in N Stiffness R2 in N/mm max. compression s2 in mm 60 43* * * * * * * * * * * * * not availble from stock, requires a minimum order quantity

14 Determining the suitable levelling element and the maximum degree of insulation Technical data 14 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 element). 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). First, the static load F for each levelling element must be determined. For well arranged levelling elements 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 elements = static load F [N] / per levelling element Once the static load F has been calculated, select a levelling element 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 elements 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 element 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. Application example

15 GN Rubber pads Pad NBR Rubber, hardness 68 Shore, black colour, oil resistant. Standard executions available - Type A: for levelling elements with two hole fl ange (d1 = 60 / 90 / 113). - Type B: for levelling elements with four-hole fl ange (d1 = 113 / 126). Features and applications Rubber pads GN in connection with GN 148 levelling feet are used for setting up machines and units if no fi rm bolt connection to the ground is required. To be fi xed to the levelling feet, they are snapped into the attachment bore holes of the fl anges. Small pimples at the bottom face of the rubber pads enhance the stability. 15 Standard Elements Main dimensions Description l1 l2 d1* d2 d3 m1 m2 s g GN A GN A GN A GN B GN B * Diameter of the levelling feet GN 148

16 OTTO GANTER GmbH & Co.KG Triberger Straße Furtwangen GERMANY Phone: Fax: info@ganter-griff.de ZDEPEGDVAENG12 ELESA S.p.A. Via Pompei Monza (MB) ITALY Phone: Fax: info@elesa.com