Shock damper

vibrationanti-vibrationfluid

Overview
LEBEN supplies industrial shock absorbers in custom single-unit or small-series production. Offerings include vibration absorbers, special/custom shock absorbers and fluid-elastomer (hydrostatic/visco-elastic) buffers designed to meet project-specific load, stroke and installation requirements.

Tension/compression shock absorbers
Custom TwinStroke® designs provide energy dissipation in both tension and compression directions. A single element absorbs bidirectional loads immediately without idle stroke, reducing weight and installation space compared with two-element solutions.

Operating principle
As a purely hydraulic TwinStroke® variant:

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

The piston system transfers forces gas-hydraulically to separate gas and oil chambers, enabling low-wear absorption of alternating loads. Return-stroke damping can be integrated to limit tension-side force peaks.

Structure
Hydraulic variants include piston, piston rod, gas and oil chambers and damping medium. Alternative designs combine hydraulic damping with a mechanical friction spring for return in tension direction:

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

Hydrostatic / Visco-elastic / Fluid-elastomer shock absorbers
These elements combine spring and damping functions via a compressible filling (elastomeric fluid) inside a cylinder. Available for compression (series ED) and/or tension (series EZ). Main variable parameters: cylinder volume, piston/piston-rod diameters, preload force and throttling to shape the characteristic curve.

Advantages

• Bidirectional use (tension and compression)
• Adjustable characteristic curves (linear, progressive, near-horizontal, degressive)
• Compact design with high energy absorption
• High spring preload and integrated return without separate gas or coil spring
• High-viscosity elastomer fluid can improve leakage safety
• Maintenance-free designs where applicable

Disadvantages

• Lower dissipation compared with some hydraulic principles (C-Type, S-Type)
• High preload forces may be problematic for specific applications
• High filling pressure can increase leakage risk
• Low-speed load cycles may require higher counter-forces versus hydraulic variants

Example specification

• Total length of the shock absorber: 3.7 m
• Weight: approx. 1.4 t
• Application: hydrostatic buffer for damping a pre-tensioned cable-catch system

Typical applications

• Train couplings / drawgear
• Locks and lock gates
• Severe-duty industrial machinery
• Amphibious vehicle suspension
• Underground shuttles and cable-car cabins

Vibration absorbers
Manufactured as customer-specific single-tube or twin-tube variants:

• Single-tube: tension and compression damping in any mounting position; minimal diameter with increased length
• Twin-tube: tension and compression damping, preferred vertical mounting; shorter overall length, larger diameter; damping can be progressive or degressive

Swivel piston shock absorber
Displacement-type dampers with hydraulic flow resistance for pendulum or swing damping (e.g., cable-car cabins). Designs are project-specific; no standard unit.

Retrofit / Replacement
LEBEN can supply replacement shock absorbers compatible with many third-party manufacturers, matching damping characteristics and dimensions for retrofit projects.

Suspension strut (gas-hydraulic shock absorber)

• Bidirectional use (tension and compression)
• Compact installation and variable preload force
• Examples: amphibious vehicle wheel suspension, underground shuttle struts; optional on-the-fly stiffness regulation and nitrogen gas spring accumulators

Design flexibility
LEBEN adapts reaction-force and deceleration curves via tailored throttling concepts; custom requests are feasible even for small quantities.

Technical specifications

• Manufacturer: LEBEN-Dämpfungstechnik GmbH
• Key technologies: TwinStroke® (hydraulic reversible), hydrostatic / visco-elastic / fluid-elastomer (ED/EZ series), gas-hydraulic buffers
• Main components (fluid-elastomer buffers): cylinder, compressible filling, high-pressure seals, piston, piston rod, guide bearing
• Series names: ED (compression), EZ (tension); TwinStroke®
• Functional capabilities: tension/compression damping, variable characteristic curves, integrated spring return, optional return-stroke damping
• Manufacturing: single-unit or small-series, bespoke designs
• Example dimensions: total length up to 3.7 m; weight approx. 1.4 t (project dependent)