Asymmetric Bogie Frame Longitudinal Beams for Wider Rail Vehicle Aisles

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional bogie structures for low-floor rail vehicles limit the width of the aisle, making it difficult to arrange seats asymmetrically, such as in a 2 + 1 pattern, due to the symmetrical placement of longitudinal beams between rail wheels.

Innovation Solution

The bogie frame's longitudinal beams are placed asymmetrically with respect to the center line, one within and one outside the area between the rail wheels, allowing for the placement of traction devices on one side and braking devices on the other, which can be accommodated at the outer edges, enabling a wider aisle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If longitudinal beams are placed symmetrically between rail wheels, then structural stability is maintained, but aisle width is limited

Engineering Contradiction:
Improveaisle widthVSAvoidbogie symmetry
Core Design Contradiction:
Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent applies asymmetry by positioning one longitudinal beam inside the area between rail wheels and the other longitudinal beam outside this area at the outer edge of the bogie. This asymmetric arrangement breaks the traditional symmetric structure, enabling the aisle width to be increased while maintaining structural functionality through compensating design elements.

Inventive Principle:
Principle #4Asymmetry

2Area of stationary object

If longitudinal beams are placed asymmetrically, then aisle width increases, but device complexity increases

Engineering Contradiction:
Improveaisle widthVSAvoidbogie structure
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent applies local quality by differentiating the positions of the two longitudinal beams - one inside and one outside the rail wheel area - while maintaining other structural elements in symmetric positions. This localized asymmetric arrangement allows aisle width expansion without requiring complete redesign of the entire bogie structure, thereby limiting the increase in overall complexity.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If longitudinal beams are placed asymmetrically, then seating flexibility improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improveseating arrangement flexibilityVSAvoidbeam positioning precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent implements asymmetry in longitudinal beam positioning to enable flexible seating arrangements such as 2+1 patterns. The asymmetric structure provides the necessary spatial flexibility for various seating configurations while the precision requirements are managed through standardized manufacturing tolerances and modular design approaches.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3079964B1Bogie and carriage structure for rail vehicle
Publication Date: 2019.02.06 HELSINGIN KAUPUNGIN LIIKENNELIIKELAITOS
  • EP3079964B1 patent drawingFigure 1~3
  • EP3079964B1 patent drawingFigure 4

AI summary

The invention relates to a bogie (4) for a rail vehicle, the bogie comprising a bogie frame (5) arranged to be fastened to the rail vehicle; two longitudinal beams (7, 8) of the bogie frame that are provided on opposite sides of the bogie and parallel to a direction of travel of the bogie; and rail wheels (9) supported on the longitudinal beams, adjacent thereto. One longitudinal beam (7) is placed within an area between the rail wheels (9) located on the opposite sides of the bogie, and the other longitudinal beam (8) is placed outside said area between the rail wheels (9), at an outer edge of the bogie, the longitudinal beams (7, 8) thus being located asymmetrically with respect to a centre line of the bogie. The invention also relates to a carriage structure for a rail vehicle provided with such a bogie.