Railway Wheelset Reprofiling via Underfloor Lathe Precision
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Solution Overview
Problem
Existing methods for reprofiling railway wheelsets on underfloor lathes are not capable of achieving highly accurate results necessary for high-speed vehicles, and they require material removal that is not minimal, which affects the cost-effectiveness and mileage of the wheelsets.
Innovation Solution
A method involving lifting and fixing the wheelset using drive rollers and axial guide rollers, applying additional force, determining the actual diameter and wear profile, and performing a single machining cut with precise cutting depths to restore the nominal profile without removing material from the wheel flange, ensuring rigid clamping and accurate machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wheelsets are reprofiled on conventional lathes using forming operations, then material can be displaced to fill worn areas, but the process is complex and requires specialized equipment not available on underfloor lathes
Solution Approach 1:
The patent extracts the forming operation from the reprofiling process, eliminating the need for complex forming equipment on underfloor lathes. Only simple cutting tools are retained, while the material displacement function is removed, allowing reprofiling to be achieved through precise cutting alone
Solution Approach 2:
The patent changes the machining parameters by limiting cutting depth to 0.1-0.2mm and controlling maximum deviation from nominal diameter to 0.1mm. These parameter changes enable high-precision reprofiling through simple cutting operations without requiring complex forming equipment
2Manufacturing precision
If wheelsets are reprofiled by removing material from the wheel flange, then the nominal contour can be restored, but significant material is removed reducing wheelset mileage
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different wheel areas. The wheel flange is excluded from material removal (cutting depth 0mm), while only the running surface and tread area are machined with minimal cutting depth of 0.1-0.2mm, preserving flange material while restoring the nominal contour where needed
3Manufacturing precision
If wheelsets are removed from vehicles for reprofiling, then accurate machining can be performed, but operational time is lost and cost-effectiveness is reduced
Solution Approach 1:
The patent enables the underfloor lathe to perform reprofiling operations in-situ on the vehicle, making the system self-sufficient. The wheelset remains mounted on the vehicle throughout the machining process, eliminating the need for removal and subsequent reinstallation, thus maintaining operational continuity while achieving high machining precision
4Loss of substance
If multiple machining cuts are used to reprofile wheelsets, then material removal can be controlled, but the process time increases and productivity decreases
Solution Approach 1:
The patent achieves continuous useful action by completing the entire reprofiling operation in a single cutting pass. The machining process continuously removes material across the required areas without interruption or multiple setup operations, simultaneously controlling material removal at 0.1-0.2mm depth and maximizing productivity through uninterrupted machining
Data Source
AI summary
The invention relates to a method for reprofiling wheelsets (1) rotatably mounted in axle bearing housings (6) on rail vehicles on underfloor wheelset lathes (12; 14) equipped with machining tools, a machine control for the machining tools, drive rollers (15), axial guide rollers (17), measuring rollers (13) as well as clamping devices (21; 22) to engage the axle bearing housings (6). The method is characterised in that the wheelset (1) is lifted off the rail using the drive rollers (15), weighing it in the process, the axle bearing housings (6) are fixed between the drive rollers (15) and the clamping devices (21; 22), an axial guide roller (17) is adjusted to touch the inner side (16) of each of the two wheels (3; 4) of the wheelset (1) and fixed in this position, an additional force (20) is applied to the drive rollers (15), that the actual diameter (8) and the wear profile of each wheel (3; 4) is determined by means of a measuring roller (13), that the smaller actual diameter is determined based on the measurement results and, it having been modified by a specified machining allowance, entered as the nominal diameter (11) into the machine control for the machining tools.