Rail Vehicle Damping System with Nested Hydraulic Chambers

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Solution Overview

Problem

Existing shock absorbers in rail vehicles are limited in their ability to effectively dampen both tensile and compressive forces over a wide range without wearing out and have a long overall length.

Innovation Solution

A damping system comprising a spring apparatus and a hydraulic damping device, where the spring apparatus is compressed between a stationary and a displaceable stop, and hydraulic fluid flows between chambers to counteract movement, providing both tensile and compressive force damping without wear through a throttled overflow system and a multiplier valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a spring apparatus and hydraulic damping device are used to dampen both tensile and compressive forces, then the damping effectiveness over a wide range is improved, but the overall length of the device increases

Engineering Contradiction:
Improvedamping effectivenessVSAvoidoverall length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent implements nesting by placing the first hydraulic chamber inside the second hydraulic chamber, with the piston rod and piston head arranged concentrically within the chamber structure. This nested configuration allows both tensile and compressive damping functions to be integrated in a compact arrangement, reducing the overall length while maintaining the required damping effectiveness across a wide force range.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Force

If a drawbar/buffering device with spring apparatus is used to transmit tensile and compressive forces, then the force transmission capability is improved, but the device complexity increases

Engineering Contradiction:
Improveforce transmission capabilityVSAvoiddevice complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by designing a single integrated damping system that handles both tensile and compressive forces through the coordinated action of the spring apparatus and the dual-chamber hydraulic system. The piston rod serves multiple functions: transmitting force, actuating the piston head, and regulating hydraulic fluid flow. This universal design reduces device complexity compared to separate tensile and compressive buffering devices while maintaining full force transmission capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the spring apparatus and hydraulic damping device into a single integrated system where both components work together to dampen forces in both tension and compression. The first and second hydraulic chambers are combined with the spring apparatus positioned between them, creating a unified structure that replaces what would traditionally require separate buffering devices for tensile and compressive loads.

Inventive Principle:
Principle #5Merging (Combining)

3Loss of energy

If traditional shock absorbers are used to absorb collision energy, then the energy absorption capability is improved, but the wear and durability decrease

Engineering Contradiction:
Improveenergy absorption capabilityVSAvoidwear and durability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent employs hydraulic damping by using hydraulic fluid that flows through restricted passages in the first and second hydraulic chambers. This hydraulic mechanism dissipates collision energy through fluid friction and pressure changes rather than through mechanical contact and deformation. The spring apparatus provides elastic energy storage and recovery without wear. This combination of hydraulic damping and elastic recovery eliminates the wear associated with traditional mechanical shock absorbers while maintaining effective energy absorption capability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively dampens both tensile and compressive forces over a wide range without wear, maintaining hydraulic forces constant and reducing the overall length of the device.

Implementation Method 1

the spring apparatus accommodated between the first and the second stop is subjected to pressure and is compressed. The compression force of the spring apparatus counteracts the movement of the second stop

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

hydraulic fluid flows in a throttled manner from the first hydraulic chamber to the second hydraulic chamber or from the second hydraulic chamber to the first hydraulic chamber

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP2305531B1Device for damping forces of traction and compression
Publication Date: 2012.02.22 VOITH PATENT GMBH
  • EP2305531B1 patent drawingFigure 1
  • EP2305531B1 patent drawingFigure 2
  • EP2305531B1 patent drawingFigure 3

AI summary

The device (100) has a damping system (10) held in a housing (11) and provided with a spring apparatus (12) and a hydraulic damping equipment, which comprises over-flow systems. A piston rod (2) is movable relative to the housing in a longitudinal direction (L). Hydraulic fluids are flown from a rear hydraulic chamber area and one of hydraulic chambers (18) over a spherical non-return valve into a front hydraulic chamber area (17a), during longitudinal movement of a piston head (3) relative to another hydraulic chamber (17) towards the rear chamber area, using one of the overflow systems.