Hydropneumatic Suspension with Arched Spring Segments

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Solution Overview

Problem

Existing rail vehicle suspension systems face challenges in replacing air springs with hydropneumatic solutions that are complex and costly, requiring complex mechanical implementations to accommodate vertical, transverse, longitudinal movement, and rotation, while also risking bearing jamming due to dirty roller bearings.

Innovation Solution

A hydropneumatic suspension system with arched end segments and layered spring segments, integrated with a hydraulic cylinder and piston, and a pressure accumulator, allowing for adjustable damping characteristics and reduced complexity, enabling 'airless' trains without compressed air supply, featuring a compact and lighter running gear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If air springs are used for suspension, then vertical rigidity is reduced for comfort, but complex mechanical solutions are required to replace them with hydropneumatic suspension

Engineering Contradiction:
Improvevertical rigidityVSAvoidmechanical solution complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent extracts the complex mechanical components (roller bearings, transverse suspension mechanisms) from the hydropneumatic suspension system and replaces them with a simpler direct connection between the hydraulic cylinder and the vehicle body, achieving the same suspension function with reduced complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The hydraulic cylinder arrangement serves multiple functions simultaneously: vertical suspension, transverse rigidity control, and longitudinal movement accommodation, eliminating the need for separate specialized components for each function

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

2Adaptability or versatility

If roller bearings are used in hydropneumatic suspension, then transverse characteristics can be generated, but the bearings are prone to jamming when dirty

Engineering Contradiction:
Improvetransverse characteristicsVSAvoidbearing reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent removes the roller bearings entirely from the suspension system, replacing them with a direct mechanical connection that does not require rolling elements, thereby eliminating the risk of bearing jamming while maintaining transverse rigidity through the structural design of the connection points

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces rigid connection elements (fastening plates, mounting brackets) as intermediaries between the hydraulic cylinder and the vehicle body, which transmit transverse forces without requiring rolling elements, thus avoiding bearing-related reliability issues

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If air springs are replaced with hydropneumatic suspension, then compressed air supply is eliminated, but the system becomes more expensive and complex

Engineering Contradiction:
Improvecompressed air supplyVSAvoidsuspension system complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent replaces the pneumatic system (air springs, compressed air supply) with a hydraulic system (hydraulic cylinder, piston, fluid reservoir), using liquid hydraulics instead of gas pneumatics to achieve the same suspension function with different mechanical characteristics

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and eliminates the compressed air supply system from the vehicle, replacing it with a self-contained hydraulic system that uses incompressible fluid to provide suspension forces, thereby removing the need for expensive air compression infrastructure

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution provides improved suspension with reduced complexity, enhanced vertical damping, and adjustable transverse rigidity, enabling the development of 'airless' trains with smaller, lighter, and cheaper running gear, while minimizing the risk of bearing jamming and maintaining comfort and stability.

Implementation Method 1

a hydraulic cylinder arrangement (2) with a hydraulic cylinder (3) and a cylinder piston (4) that can be moved back and forth therein, so that when a vertical force is applied, which leads to a pushing in of the hydraulic cylinder (3), the desired damping characteristics come into play

Methodology Applied
Scientific EffectHydraulic damping: Viscous Damping

Implementation Method 2

Both the hydraulic cylinder (3) and the cylinder piston (4) have a fastening plate (7) on their respective distal section, on which a spring segment (5, 6) is arranged

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

a pressure accumulator (9), which is connected to the chamber of the hydraulic cylinder arrangement (2) that can be compressed by the cylinder piston (4) via a connecting line (11)

Methodology Applied
Scientific EffectHydraulic pressure accumulation: Hydraulic Accumulator

Data Source

PatentEP3892515B1Hydropneumatic suspension for a vehicle
Publication Date: 2023.06.21 LIEBHERR TRANSPORTATION SYST
  • EP3892515B1 patent drawingFigure 1~2
  • EP3892515B1 patent drawingFigure 3a~3f
  • EP3892515B1 patent drawingFigure 4

AI summary

The present invention relates to a hydropneumatic suspension (1) for a vehicle, in particular a rail vehicle, comprising a hydraulic cylinder arrangement (2) with a hydraulic cylinder (3) and a cylinder piston (4) movable back and forth in the hydraulic cylinder, a first spring segment (5) arranged at one of the two longitudinal ends of the hydraulic cylinder arrangement, and a second spring segment (6) arranged at the other of the two longitudinal ends of the hydraulic cylinder arrangement, wherein the respective longitudinal ends of the hydraulic cylinder arrangement and the associated spring segments are each designed such that they form an arc shape curved inwards towards the hydraulic cylinder arrangement.