Variable Length Steering Link for Railway Bogie Wheel Wobble
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Solution Overview
Problem
Rail network bridges and structures are often too low for standard wagons to carry containers, leading to inefficiencies and increased costs when attempting to reduce wheel diameter for lower bed height, which results in wheel wobble and high costs for self-steering bogies.
Innovation Solution
A variable length steering link assembly with telescopic contraction and extension capabilities, utilizing identical anchor portions and springs, and hard stops for controlled movement, allowing for economic manufacturing and assembly, and reducing the need for expensive self-steerable wheel sets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If wheel diameter is reduced to lower bed height, then containers can be carried on low bridges, but wheel wobble increases and cornering forces become more sensitive
Solution Approach 1:
The steering link assembly is made variable length through telescopic chambers that can extend and contract dynamically. This allows the link to adapt its length in response to cornering forces and wheel movement, providing active compensation for the instability caused by smaller wheel diameter while maintaining controlled wheelset movement through the frame.
2Reliability
If self-steering bogies are used to manage cornering forces, then wheel wobble is reduced, but manufacturing cost increases significantly
Solution Approach 1:
The steering link assembly is divided into multiple segments including a central link element, two head elements, and two anchor portions. Each anchor portion can telescopically house a head element, allowing the assembly to be constructed from modular, standardized components that are easier to manufacture and assemble compared to monolithic self-steering bogies.
Solution Approach 2:
The telescopic steering link assembly acts as an intermediary mechanism between the wheelset and the frame. It provides the necessary steering function and damping of cornering forces through its variable length capability, eliminating the need for expensive self-steering bogies while maintaining reliable wheelset control.
3Reliability
If variable length steering link assembly is used, then wheel movement is controlled during curving, but device complexity increases
Solution Approach 1:
The anchor portions are designed to telescopically house the head elements within their chambers. This nesting arrangement allows the variable length mechanism to be compact when not in use and expand only when needed for cornering forces, reducing overall structural complexity while maintaining the variable length capability for controlled wheel movement.
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 effectively manages wheel movement during curving without the need for expensive self-steerable wheel sets, maintaining efficiency and reducing wheel wobble, while allowing for easy tuning and assembly, thus addressing the limitations of smaller wheel diameters and high costs associated with existing solutions.
Implementation Method 1
Each chamber (30) also contains a compression spring (31) and a rigid cylinder (32) which is circumjacent the spring (31)
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
This invention relates to steering links (19) for bogies (11) and to wagons (10) incorporating such bogies, a variable length steering link (19) assembly for a bogie including an elongate link (22) having a generally T-shaped head (23) at each end and an anchor (24) for each end, wherein each anchor defines an axially extending chamber (30) for slidably receiving a respective head an a compression spring (31) wherein in one chamber the spring acts on the end fact of its associated head and in the other chamber the spring acts on the back face of its associated head.