Special Shock Reducing & Vibration Absorbing Elements
Industrial Shock Absorber, Vibration Damper, Special Shock Absorber and Fluid-Elastomer / COMPENSER®
LEBEN provides customized shock absorbers in variants (vibration damper, special shock absorber and fluid-elastomer), as individual piece according to individual customer requirement and design.
Push & Pull Buffer
This design by LEBEN-Dämpfungstechnik GmbH acts as a hydraulic shock absorber in both, pulling and pushing direction. The energy dissipation of this kind of industrial shock absorber is performed in two ways:
Working principle:
As a purely hydraulic variant (TwinStroke®):
– in push (compression) direction hydraulically reversible by means of damping medium
– in pull (tension) direction hydraulically reversible by means of damping medium
The TwinStroke® dampens push and pull forces without an additional functional element. A piston system transmits the push and pull forces gas-hydraulically to different gas and oil chambers. In this way, any load can be absorbed immediately without idle stroke, so-called “slack”, and with minimal wear. The TwinStroke® can absorb changing loads very well.
The smaller size and lower weight is advantageous, as only one element is needed to absorb compression and tension forces. In addition, this design is more cost-effective than a comparable two-element system, as it eliminates the need for a mechanical friction spring in the direction of pull. If necessary, this hydraulic buffer can be easily replaced.
Design:
As a hydraulic variant in combination with a mechanical spring:
– in push (compression) direction hydraulically reversible by means of damping medium
– in pull (tension) direction, mechanically reversible by means of friction spring
In addition, the buffer is equipped with return stroke damping to avoid impermissible force peaks in the direction of pull.
Hydrostatic / Visco-Elastic / Fluid-Elastomer Buffer
Shock reducing elements of LEBEN-Dämpfungstechnik GmbH with integrated spring-damper operating principle known as hydrostatic, visco-elastic, elasto-fluid shock absorbers or fluid-elastomer buffers.
We offer these types in push direction (type designation of series “ED”) and/or in pull direction (series “EZ”).
In general, our fluid-elastomer buffers have the following main components: Reservoir (cylinder), filling preload with a compressible fluid, high pressure sealing system, piston, piston rod and guide bearing.
Variable parameters include volume of the cylinder, diameter of the piston and piston rod, preload and means of throttling, so that the visco-elastic spring-damper perfectly meets the requirements of your application.
Advantage:
- usage in push and in pull direction (“in tension and compression”)
- variable characteristic (linear, progressive, approximately horizontal or degressive)
- small design with high energy absorption
- very high preload of the spring (depending on the application individual reset force of the piston rod)
- integrated spring return without additional gas spring or mechanical coil spring
- highly viscous elastomer fluid can increase leakage safety
- maintenance-free operation
Disadvantage:
- lower degree of dissipation compared to hydraulic principle (see C-Type and S-Type)
- high preload force of spring possibly problematic
- high pressure of container can increase risk of leakage
- operational push-in cycles of the piston rod at creep speed with low counterforces are not possible in contrast to hydraulic principle (see C-Type and S-Type)
Operating principle of the ED/EZ series:
Highly viscous, elastic fluids make it possible to design fluid-elastomer dampers based on the principle of hydrostatic compression.
Suspension: The movement of the piston rod reduces the volume of the cylinder filled with silicone elastomer. Compression of the fluid results in increased internal pressure and counteracts the movement of the piston. This is referred to as compressibility.
Damping: The movement of the piston creates a flow path (by means of throttle orifices or annular gap) along the piston. The reaction force of the piston due to laminar flow and viscosity depends on the speed of the movement.
Used as a buffer in:
Illustrated hydrostatic buffer:
Damping of the pre-tensioned rope catch (tensioned catch rope) in front of a water lock.
Special feature:
- Total length of the shock absorber cylinder: 3,7 m
- Weight: approx. 1.4 t
Vibration Damper
Vibration absorbers are produced in several configurations:
Single Tube Vibration Absorber:
for pull and push absorption at random mounting positions.
The length is increased to keep the diameter dimension at a minimum.
Twin Tube Vibration Absorbers:
for pull and push absorption. The preferred mounting position is vertically aligned. Compared to single tube absorbers, the length is decreased, while the diameter is enlarged.
The characteristic of damping for both types can be progressive or degressive.
(Detailed information concerning application and calculation can be found in the VDI-Guideline: VDI 3833 Bl.1+2 – German Association of Engineers Guideline.)
Rotating Piston Absorber
Rotating Piston Absorbers are displacement absorbers using hydraulic flow resistance.
They are used to damp rotational vibrations, e.g. absorbers for ropeway cabins (see VDI-Richtlinie VDI 3833 German Association of Engineers, sheet 1).
The design is customized. Due to different operating conditions, no standard design is possible.
(see also VDI-Guideline, VDI 3833 sheet 1)
Retrofit – exchange of various other brands
Due to many years of experience in the field of damping technology, LEBEN is able to replace shock absorbers of other makes from various manufacturers.
The required characteristics of the damping property as well as the dimensions of these industrial shock absorbers to be replaced can usually be met by a replacement shock absorber made by LEBEN-Dämpfungstechnik GmbH.
Suspension Strut
Suspension strut (gashydraulic shock absorber) by LEBEN-Dämpfungstechnik GmbH
Advantage:
- Use in pulling and pushing direction
- Small design
- Variable preload force of the damper
Used as a buffer in:
- Amphibious vehicle
- Underground shuttle
- …
Illustrated suspension strut:
Damping of the independent suspension of an amphibious vehicle
Special feature:
- Nitrogen gas spring as triple membrane accumulator
- Regulation of the spring stiffness while driving
Various Dampers
Increasing demands on machines, vehicles and production facilities in terms of speed and mass cause considerable vibration problems. In many cases, the occurring magnitudes of frequency and amplitude exceed the in series produced standard dampers. Also space problems or missing connection parts for already existing plants require a modification of the standard program. Through state-of-the-art processes in design and production, LEBEN-Damping Technology GmbH has a high degree of flexibility and is therefore able to respond to special customer requirements even on small quantity basis.
Depending on the requirements, the reaction force or delay curve can be realized by individual throttle principle.