Railway Wheel Transverse Web Profile Design
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Solution Overview
Problem
Current railway wheel designs, such as ORE-wheels with tangential web profiles and bell-shaped webs, face high stresses and weight issues under thermal and mechanical loads, limiting their capacity to handle loads above 23.5 tnf per axle and resulting in significant lateral deformation during brake operations.
Innovation Solution
A railway wheel design with a transverse web profile where the theoretical midline passes through specific points matching the rim and hub, featuring external and internal radius curves that optimize web thickness and curvature, reducing stress and weight while maintaining structural integrity under high loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the thickness of the web and walls of the hub is increased to handle higher axle loads, then the load capacity is improved, but the weight of the wheel increases
Solution Approach 1:
The web thickness is optimized locally rather than uniformly. The web is thickest at the hub-web junction where mechanical loads are highest, and gradually thinns toward the rim while maintaining adequate thickness for thermal load resistance. This localized thickness distribution allows the wheel to handle high axle loads without the weight penalty of a uniformly thick web.
Solution Approach 2:
The web profile employs curved transitions instead of straight lines, with the outer surface defined by radius curves (R1, R2, R3, R4) and the inner surface by radius curves (R5, R6, R7, R8). These curved profiles optimize stress distribution and allow gradual thickness variation, enabling the web to withstand high loads while minimizing material usage and weight.
2Strength
If the web thickness is increased in the zone matching the hub to reduce mechanical stress, then the strength is improved, but the weight and thermal stress level are greatly increased
Solution Approach 1:
The web thickness is precisely controlled at different locations: it is maximum at the hub-web junction (second point) to resist mechanical loads, but reduces toward the rim (first point) where thermal loads dominate. The ratio of web thickness at the first point to the second point is maintained between 0.7 and 1.1, optimizing both strength and weight.
Solution Approach 2:
The curved profile of the web, defined by multiple radius curves, creates a gradual transition in thickness from the hub to the rim. This curvature allows the web to be thick where mechanical strength is needed while being thinner where weight reduction is beneficial, achieving optimal stress distribution without excessive weight.
3Weight of moving object
If a bell-shaped web profile is used to minimize weight, then the weight is reduced, but the wheel cannot handle loads above 23.5 tnf per axle
Solution Approach 1:
The web profile is designed with locally optimized thickness distribution that exceeds the bell-shaped profile at critical locations. The web is thickest at the hub-web junction (second point) to handle high mechanical loads, while maintaining overall lightweight design. This localized reinforcement enables the wheel to handle loads above 23.5 tnf per axle without significant weight increase.
Solution Approach 2:
The complex curved profile, defined by multiple radius curves with specific radius ratios, creates a more effective stress distribution than a simple bell-shaped cosine profile. The curvature allows the web to maintain adequate thickness at load-critical locations while minimizing weight, enabling higher load capacity.
4Strength
If the web profile is offset toward the external surface to increase web thickness at the hub, then the mechanical strength is improved, but the lateral deformation of the rim during thermal loading is increased
Solution Approach 1:
The web thickness distribution is precisely controlled at different radial positions. The web is thickest at the hub-web junction (second point) to resist mechanical loads, but the offset is limited (second point offset ≤ 0.1 rim width) to prevent excessive rim deformation during thermal cycling. The first point offset is also controlled (≤ 0.08 rim width) to maintain rim stability.
Solution Approach 2:
The curved web profile creates a gradual transition in thickness and position from the hub to the rim, rather than a sharp offset. This curvature distributes the structural reinforcement more evenly, providing mechanical strength at the hub while minimizing the adverse effect on rim deformation during thermal loading.
Data Source
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Figure 3a
AI summary
The invention relates to transport engineering, in particular to railway transportation vehicle wheels. Essence of invention: A railway wheel having a central plane perpendicular to an axis of rotation of the wheel which includes a rim formed by a tread surface and a flange, and also includes a hub and a web formed by external and internal surfaces and made in such a way that a theoretical midline of a transverse web profile passes through a first point located in a place of matching the web with the rim, a central point where the theoretical midline has maximum offset from the central plane in a direction opposite to the flange, and a second point located in a place of matching the web with the hub, wherein the external and internal surfaces of the web are formed by external and internal radius curves, respectively, wherein radiuses of the first and the second external radius curves for the external web surface are from 0.04 to 0.05 of a tread diameter, the radius of the third external radius curve is from 0.08 to 0.1 of the tread diameter, the radius of the fourth external radius curve is from 0.07 to 0.09 of the tread diameter, and the radius of the first internal radius curve for the internal web surface is from 0.08 to 0.1 of the tread diameter, radiuses of the second and the third internal radius curves are from 0.06 to 0.08 of the tread diameter, the radius of the fourth internal radius curve is from 0.04 to 0.06 of the tread diameter, wherein the first point is offset to a distance not more than 0.08 of the rim width from the central plane in the direction opposite to the flange, the central point is offset from the central plane to a distance within a range of values from 0.35 to 0.4 of the rim width, and the second point is offset to a distance not more than 0.1 of the rim width from the central plane towards the flange, while a ratio of a web thickness at the first point to a web thickness at the second point is from 0.7 to 1.1 and the ratio of a web thickness at the central point to the web thickness at the second point is from 0.7 to 0.9.