Rail Vehicle Suspension Spring Unit Pendulum Motion

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Solution Overview

Problem

Existing rail vehicle running gear designs face challenges in providing sufficient lateral softness for improved riding comfort while maintaining a compact and space-efficient configuration, especially in low-floor wagons where building space is limited.

Innovation Solution

Integrating the pendulum moment directly into the spring unit, allowing the spring unit to respond to uneven loads by deflection in the height direction, thus generating pendulum motion and reducing the need for additional components and space, while using the spring unit's primary elasticity for lateral excursion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If additional components (laminated rubber metal spring, bolster) are added to provide lateral softness, then riding comfort is improved, but device complexity and building space requirements increase

Engineering Contradiction:
Improveriding comfortVSAvoidnumber of components
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines the functions of the spring unit and pendulum unit into a single integrated component. The spring unit is designed to perform both vertical support and lateral pendulum motion, eliminating the need for separate bolster and rubber metal spring components. This merging reduces device complexity while maintaining the lateral softness needed for riding comfort.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring unit is designed as a multi-functional component that simultaneously provides vertical load support, lateral pendulum motion for comfort, and articulation functions. This universal design allows a single component to replace multiple specialized components, reducing overall system complexity.

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

2Ease of operation

If additional components (laminated rubber metal spring, bolster) are added to provide lateral softness, then riding comfort is improved, but building space requirements increase

Engineering Contradiction:
Improveriding comfortVSAvoidbuilding space
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

By merging the spring unit and pendulum unit into a single integrated component, the patent eliminates the need for separate bolster and rubber metal spring components. This reduces the overall building space required while maintaining the lateral softness needed for riding comfort.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pendulum unit is nested within or integrated with the spring unit structure, allowing the lateral motion mechanism to occupy the same spatial envelope as the vertical support spring. This nesting approach minimizes the total building space required compared to separate components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Length of moving object

If a U-shaped bolster design is used to achieve low floor height, then floor height is reduced, but transverse dimension availability is limited

Engineering Contradiction:
Improvefloor heightVSAvoidtransverse dimension
Core Design Contradiction:
Length of moving objectVSArea of moving object

Solution Approach 1:

The patent merges the bolster function into the spring unit itself, eliminating the need for a separate U-shaped bolster structure. This allows the transverse dimension to be optimized for passenger space while maintaining low floor height, as the spring unit directly provides the lateral support function without requiring additional U-shaped shanks.

Inventive Principle:
Principle #5Merging (Combining)

4Device complexity

If conventional spring designs are used, then structural simplicity is maintained, but lateral softness is insufficient

Engineering Contradiction:
Improvestructural simplicityVSAvoidlateral softness
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The spring unit is designed to dynamically respond to lateral loads by enabling pendulum motion. Rather than being a static rigid spring, the unit can rotate and deflect laterally, providing the needed softness. This dynamic behavior allows conventional spring materials to achieve lateral compliance without adding complex structures.

Inventive Principle:
Principle #15Dynamics

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

This configuration results in a more space-saving and cost-effective suspension system with adjustable transverse rigidity, enhancing riding comfort and dynamic behavior without increasing the number of components, and allowing for a nested design that minimizes space usage.

Implementation Method 1

the spring unit (which is arranged in such a manner that its primary support is provided in the height direction) may easily respond to such an uneven load in the height direction by uneven deflection in the height direction, thereby generating or defining, respectively the tilt or pendulum motion of the pendulum unit

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The first articulation and the second articulation allow relative motion between the running gear frame unit and the traverse unit in the transverse direction and/or in the longitudinal direction by a pendulum motion of the pendulum unit

Methodology Applied
Scientific EffectPendulum motion: Pendulum

Data Source

PatentEP3365217B1Running gear unit for a rail vehicle
Publication Date: 2021.08.25 BOMBARDIER TRANSPORTATION GMBH
  • EP3365217B1 patent drawingFigure 1~2
  • EP3365217B1 patent drawingFigure 3~6
  • EP3365217B1 patent drawingFigure 7~8

AI summary

The present invention relates to a running gear unit for a rail vehicle, comprising a running gear frame unit (104), a traverse unit (109), and a suspension unit (106), in particular, a secondary suspension unit. The running gear frame unit (104) is configured to be supported on at least one wheel unit and defines a longitudinal direction, a transverse direction and a height direction. The traverse unit (109) is configured to support a wagon body (101.1) unit of the rail vehicle. The suspension unit (106) suspends the traverse unit (109) to the running gear frame unit (104). The suspension unit (106) comprises at least one spring unit (110) and at least one pendulum unit (111) arranged kinematically in series in a force flux between the running gear frame unit (104) and the traverse unit (109). The at least one pendulum unit (111) has a first end section with a first articulation (111.3) associated to the running gear frame unit (104) and a second end section with a second articulation (111.4) associated to the traverse unit (109). The first articulation (111.3) and the second articulation (111.4) allow relative motion between the running gear frame unit (104) and the traverse unit (109) in the transverse direction and/or in the longitudinal direction by a pendulum motion of the pendulum unit (111). The first articulation (111.3) and/or the second articulation (111.4) is formed by the at least one spring unit (110).