Railcar Reversing Gear Segmentation for Coaxial Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing railcar drive devices often have the reversing gear arranged on the vehicle axle, which complicates manufacturing, maintenance, and increases costs, as well as leading to misalignment issues due to non-coaxial input and output shafts.

Innovation Solution

The reversing gear is designed as a separate unit positioned behind the main gear on the vehicle frame, allowing for coaxial input and output shafts and enabling separate replacement and adjustment, with a countershaft gear stage for direction switching, and an automatic transmission with a hydrodynamic torque converter for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the reversing gear is arranged on the vehicle axle, then the drive train is compact, but the manufacturing and maintenance complexity increases

Engineering Contradiction:
Improvedrive train compactnessVSAvoidmanufacturing and maintenance complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The drive train is segmented into modular components: the reversing gear is separated from the vehicle axle and positioned on the vehicle frame as an independent unit. This segmentation allows the reversing gear to be manufactured, maintained, and replaced separately from the axle assembly, reducing overall system complexity while maintaining compact arrangement through strategic positioning.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the reversing gear is arranged on the vehicle frame, then the manufacturing and maintenance is simplified, but the alignment of drive components becomes more complex

Engineering Contradiction:
Improvemanufacturing and maintenance simplicityVSAvoiddrive component alignment
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

A cardan shaft is introduced as an intermediary component between the reversing gear (on the vehicle frame) and the final drive (on the vehicle axle). This cardan shaft accommodates angular misalignments and positional variations, serving as a flexible mediator that connects the separated components while compensating for alignment challenges through its universal joint mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the input shaft and output shaft of the reversing gear are arranged non-coaxially, then the direction switching is achieved, but the alignment of the drive train deteriorates

Engineering Contradiction:
Improvedirection switching capabilityVSAvoiddrive train alignment
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The reversing gear is designed with segmented gear stages (first and second gear stages) that allow the input and output shafts to be arranged coaxially. The direction reversal function is achieved through the gear meshing relationships within these stages rather than through non-coaxial shaft arrangement, thereby maintaining both alignment precision and operational functionality.

Inventive Principle:
Principle #1Segmentation

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 arrangement simplifies manufacturing, reduces costs, ensures proper alignment, and allows for efficient gear operation and direction switching, while enabling the use of standard commercial vehicle transmissions and reducing manufacturing complexity.

Implementation Method 1

an automatic transmission with a hydrodynamic torque converter for efficient operation

Methodology Applied
Scientific EffectHydrodynamic torque converter:

Data Source

PatentEP2608995B1Drive arrangement for a railcar
Publication Date: 2017.08.23 ZF FRIEDRICHSHAFEN AG
  • EP2608995B1 patent drawingFigure 1
  • EP2608995B1 patent drawingFigure 2

AI summary

The invention relates to a drive arrangement for a railcar which has a vehicle chassis (R) and at least one bogie (2) comprising at least one drivable vehicle shaft (3, 4), the drive arrangement (1) comprising a driving machine (5) in the form of an internal combustion engine, a transmission (7), a reversing gear, at least one universal-joint shaft (6, 10) and a final drive (11), the driving machine (5) and the transmission (7) being disposed on the vehicle chassis (R) and the final drive (11) being disposed on the bogie (2). According to the invention, the reversing gear (9) is designed as an independent structural unit, disposed in the power flow direction behind the transmission (7), and secured on the chassis (R).