Ball Joint Shell with Variable Radial Thickness
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Solution Overview
Problem
Ball joints suffer from uneven load distribution, leading to local overloading and potential damage, especially under high loads, due to the inhomogeneous loading of the spherical shell, which results in reduced maximum load capacity and increased manufacturing costs.
Innovation Solution
The spherical shell is designed with a variable radial thickness, with increased thickness in the main load area and decreased thickness in the transverse area, allowing for even force distribution over a larger angular range, using a combination of pitch circles and elliptical contours to optimize load distribution and manufacturing ease.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the spherical shell has constant thickness, then the manufacturing is simple, but the load distribution is inhomogeneous leading to local overloading
Solution Approach 1:
The spherical shell is designed with variable thickness where the wall thickness increases in the direction of the main load axis (poles) and decreases in the transverse direction (equator). This local variation in thickness distributes the load more evenly across the shell surface, preventing local overloading while maintaining manufacturing feasibility through injection molding processes.
2Strength
If the spherical shell thickness increases in load direction, then the load-bearing capacity increases, but the manufacturing complexity increases
Solution Approach 1:
The wall thickness parameter of the spherical shell is varied systematically based on the angular position relative to the main load axis. The thickness is increased at the poles (load-bearing areas) and decreased at the equator (low-stress areas), optimizing the strength-to-weight ratio while enabling cost-effective injection molding production.
3Reliability
If the ball socket is made thicker in main load area, then the load distribution improves, but the manufacturing precision requirements increase
Solution Approach 1:
The variable thickness profile of the spherical shell is pre-designed and integrated into the injection molding tooling. The mold cavity is shaped to produce the desired thickness distribution directly during manufacturing, eliminating the need for post-processing or assembly operations and maintaining consistent precision throughout production.
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 design enhances the maximum load-bearing capacity of ball joints by 20-30% and reduces manufacturing costs, while also extending the service life by distributing forces more evenly and allowing for more precise and cost-effective production.
Implementation Method 1
the acting force spreads essentially pointwise or locally in the circumferential direction evenly over a larger area of the spherical shell
Data Source
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AI summary
The invention relates to a ball joint, in particular for a wheel suspension of a motor vehicle, having a housing (2), a joint ball (3) arranged inside the housing (2), and a ball shell (4) which is arranged between these two and which bears on its outer surface (7) against the housing inner surface (6) and on its inner surface (8) against the ball surface (5), wherein the ball shell (4) receives the joint ball (3) in a slidably movable manner and is designed elastically such that, when a force (11) acts on the ball joint (1), the joint ball (3) can be displaced with respect to the housing (2). According to the invention, the ball shell (4) has, in at least one cross-sectional view taken through the ball centre point (18), a radial thickness which varies in the circumferential direction such that the acting force (11) is distributed in the circumferential direction uniformly over the ball shell (4), in particular over relatively large areas.