Shock damper

vibrationfluidfriction

Overview
LEBEN-Dämpfungstechnik GmbH supplies customised industrial shock absorbers including industrial shock absorbers, vibration absorbers, special shock absorbers and fluid‑elastomer buffers (ED/EZ series). Products are available as single units or in small series according to customer specifications.

Tension/compression shock absorbers (TwinStroke®)
The TwinStroke® design functions as a hydraulic shock absorber in both tension and compression directions. Energy dissipation occurs in both directions via a piston and separate gas/oil chambers, enabling immediate load absorption without idle stroke.

Operating principle (TwinStroke® hydraulic variant)

• hydraulically reversible in compression via the damping medium
• hydraulically reversible in tension via the damping medium

The piston system transfers tension and compression forces gas‑hydraulically to different gas and oil chambers. The concept provides immediate damping without play, low wear, compact design and lower weight compared with equivalent two‑element systems. The hydraulic buffer is replaceable if required.

Structure (tension/compression variant with mechanical spring)

• hydraulically reversible in compression via the damping medium
• mechanically reversible in tension via a friction spring

Return‑stroke damping can be integrated to avoid excessive force peaks in tension direction.

Hydrostatic / Visco‑elastic / Fluid‑elastomer shock absorbers (ED / EZ series)
Impact‑reduction elements combining spring and damping principles (hydrostatic, visco‑elastic or fluid‑elastomer). Offered for compression (ED series) and/or tension (EZ series).

Typical main components

• container (cylinder)
• filling / preload with a compressible fluid
• high‑pressure sealing system
• piston
• piston rod
• guide bearing

Variable parameters

• cylinder volume
• piston diameter and piston‑rod diameter
• preload force
• throttling effect (flow path design)

Advantages

• suitable for tension and compression
• adjustable characteristic curve (linear, progressive, near‑flat or degressive)
• compact design with high energy absorption
• very high spring preload (custom retracting force possible)
• integrated spring return without additional gas spring or coil spring
• high‑viscosity elastomer fluid increases leakage safety
• maintenance‑free operation in many configurations

Disadvantages

• lower dissipation than purely hydraulic systems (vs. C‑Type and S‑Type)
• very high preload force of the spring may be limiting in some applications
• high filling pressure can increase leakage risk
• low‑speed operational load cycles require relatively high counter‑forces compared to hydraulic types

Special feature example

• Total length of the shown hydrostatic shock absorber: 3.7 m
• Weight: approx. 1.4 t
• Application example: hydrostatic buffer for damping a pre‑tensioned cable catch system (tensioned safety cable in front of a lock)

Operating principle of ED/EZ series
High‑viscosity, elastic fluids enable hydrostatic compression designs: piston‑rod movement reduces the elastomer‑filled cylinder volume, increasing internal pressure which counteracts piston movement. Damping is generated by flow paths (throttle bores or annular gaps) where reaction force depends on speed, flow regime and viscosity.

Use cases (ED/EZ and other types)

• train drawgear and couplings
locks and heavy hydraulic buffering applications
• various custom industrial damping requirements

Vibration absorbers
Custom designs available:

• single‑tube vibration absorber: for tension and compression in any mounting position; minimized diameter, increased overall length
• twin‑tube vibration absorber: for tension and compression (preferably vertical); reduced overall length vs single‑tube but larger diameter; characteristic can be progressive or degressive

Swivel piston shock absorber
Displacement dampers with hydraulic flow resistance to damp pendulum oscillations (e.g., cable car cabins). Designs are customer‑specific; no standard version due to varying operating conditions.

Retrofit / Replacement
LEBEN can often replace industrial shock absorbers from other manufacturers with equivalents that match damping characteristics and dimensions; custom production possible in single units or small series.

Suspension strut (gas‑hydraulic)
Gas‑hydraulic suspension struts usable in tension and compression with compact design and variable preload force. Examples: amphibious vehicles, underground shuttles. Options can include in‑drive spring stiffness regulation and a nitrogen gas spring as a triple‑diaphragm accumulator.

Design flexibility
LEBEN implements custom reaction‑force or deceleration curves via tailored throttling principles to meet constraints such as limited installation space or missing connection parts.

Technical specifications

• Brand / manufacturer: LEBEN‑Dämpfungstechnik GmbH
• Notable proprietary names: TwinStroke® (tension/compression hydraulic concept), COMPENSER® / COMPENSOL® damping media referenced on site
• ED / EZ series: fluid‑elastomer buffers (ED = compression series, EZ = tension series)
• Main components: cylinder, compressible fluid filling/preload, high‑pressure sealing, piston, piston rod, guide bearing
• Example hydrostatic buffer: length 3.7 m, weight approx. 1.4 t
• Design options: purely hydraulic TwinStroke®; hydraulic + mechanical spring (return‑stroke damping); single‑tube and twin‑tube vibration absorbers; swivel piston shock absorbers; gas‑hydraulic suspension struts
• Adjustable parameters: piston/piston‑rod diameters, cylinder volume, preload force, throttling (flow path)