Light Alloy Hub with Annular Grooves for Bearing Adhesion
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Solution Overview
Problem
In motor-vehicle applications, the adherence between a light alloy hub and a steel bearing inner ring is challenging due to thermal expansion differences, leading to potential detachment during cooling and operational conditions.
Innovation Solution
A bearing-hub assembly with a cold-formed light alloy hub, featuring annular grooves and protrusions that match the inner ring's surface, ensuring secure engagement without co-molding, using processes like orbital or hydroforming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If co-molding technology is used to join light alloy hub and steel bearing inner ring, then the assembly is produced in a single piece with simplified manufacturing, but thermal expansion differences cause detachment during cooling and operational conditions
Solution Approach 1:
The invention divides the previously integrated co-molded structure into separate components: a bearing inner ring and a hub assembly with distinct parts (cylindrical portion, flange, and annular groove). This segmentation allows each component to be manufactured and assembled independently, accommodating their different thermal expansion characteristics while maintaining structural integrity through mechanical connection features like the annular groove and rolling element engagement.
2Weight of moving object
If light alloy material is used for the hub to decrease overall assembly weight, then weight reduction is achieved, but thermal expansion differences make it difficult to ensure perfect adherence to the steel inner ring
Solution Approach 1:
The invention applies local quality by creating a specific engagement zone at the interface between the light alloy hub and steel inner ring. The annular groove and rolling element configuration provide localized mechanical interlocking and load distribution at the critical interface area, ensuring reliable adherence where thermal expansion differences are most problematic, while the rest of the hub maintains its lightweight aluminum alloy construction.
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 provides a lightweight assembly with enhanced adhesion and stability under varying temperatures, preventing detachment and maintaining structural integrity during vehicle operation.
Implementation Method 1
A bearing-hub assembly with a cold-formed light alloy hub, featuring annular grooves and protrusions that match the inner ring's surface, ensuring secure engagement without co-molding, using processes like orbital or hydroforming.
Implementation Method 2
the hertzian portion material has a different thermal behavior with respect to the structural portion material (as known a light alloy, for example aluminum, has a greater thermal dilatation than the steel one). Therefore, particularly in applications with a hub rotatable and steadily engaged to the bearing inner ring, it is particularly difficult to ensure that the two portions remain perfectly adherent each other, that is to say, they do not disjoin neither after cooling nor during working operations.
Data Source
Figure 1~2
AI summary
Bearing-hub assembly (1) having: - a rolling bearing provided with a stationary radially outer ring (2), at least a rotatable radially inner ring (4) and at least a row (31, 32) of rolling bodies (3), - a light alloy hub (9), provided with a flanged portion (10) and a cylindrical housing (11), wherein the cylindrical housing (11) is axially located inside the radially inner ring (4) and is provided with an external lateral surface (91) having a complementary shape with an internal lateral surface (41) of the radially inner ring (4).