Multi-Component Gear Structure for Stress Crack and Void Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-component wheels in prior art suffer from high wall thicknesses leading to void formation and stress cracks due to internal stresses, and have limited deformability in axial and radial directions, resulting in unfavorable stress conditions and component failure.
Innovation Solution
A multi-component wheel design featuring an inner and outer part with free-standing tabs on the end faces, allowing for axial support and increased deformability, and pockets to reduce plastic wall thickness and internal stresses, while maintaining a form-fitting and material-locking connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If constant plastic wall thicknesses are implemented in the outer part, then void formation is prevented, but stress cracking due to residual stresses is promoted
Solution Approach 1:
The patent applies local quality by creating non-uniform wall thickness distribution in the outer part. Specifically, the wall thickness varies between different regions: thicker in areas requiring structural support and thinner in areas where stress accumulation would be problematic. This localized variation in thickness prevents stress concentration while maintaining overall structural integrity, resolving the contradiction between preventing voids and preventing stress cracking.
Solution Approach 2:
The patent changes the parameter of wall thickness from constant to variable. By implementing a gradient or stepped thickness profile in the outer part, the design allows different regions to have optimized thickness values. This parameter change enables the structure to accommodate residual stresses more effectively while preventing void formation in critical areas.
2Stability of the object's composition
If reduced plastic wall thicknesses are used, then void formation is prevented, but stress cracking due to residual stresses is promoted
Solution Approach 1:
The patent implements local quality by differentiating wall thickness in specific regions. The outer part has thinner walls in areas prone to stress concentration and thicker walls in areas requiring structural support. This localized thickness variation prevents stress cracking while avoiding void formation in critical load-bearing regions.
Solution Approach 2:
The patent addresses the strength-thickness contradiction by introducing dimensional variation in the wall thickness profile. Instead of uniform reduction, the thickness is optimized in three-dimensional space, creating a gradient structure that provides both stress relief and structural integrity.
3Ease of manufacture
If the outer part is molded with constant wall thickness, then manufacturing is simplified, but deformability in axial and radial directions is limited
Solution Approach 1:
The patent applies local quality by creating region-specific wall thickness variations in the outer part. Thinner sections provide enhanced deformability in axial and radial directions, while thicker sections maintain structural support. This localized differentiation achieves both manufacturing feasibility and improved adaptability.
Solution Approach 2:
The patent introduces dynamic characteristics by enabling the outer part to deform in response to operational requirements. The variable thickness design allows the structure to flex and adapt in axial and radial directions, transforming a static, rigid component into a more dynamic and adaptable system.
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 design effectively prevents void formation and stress cracks, enhancing deformability and reducing internal stresses, thereby improving the structural integrity and reliability of the multi-component wheel.
Implementation Method 1
the inner part is inserted into an injection mold, and then liquefied plastic is introduced into the injection mold via at least one injection section. By overmolding the inner part with the plastic, a form-fit and/or material-fit connection between the outer part and the inner part is achieved.
Implementation Method 2
The outer part has at least one tab on the first and/or second end face that is free in the direction of rotation about the axis of rotation and projects beyond the respective end face of the inner part.
Implementation Method 3
pockets to reduce plastic wall thickness and internal stresses
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
The present invention relates to a multi-component gear (1) with an axis of rotation (X) and a first end face (11) and a second end face (12), comprising an inner part (20) and an outer part (30) made of a plastic with at least one injection-molded section (32), wherein the outer part (30) is arranged on an outer circumferential surface (24) of the inner part (20) in a form-fitting and/or material-locking manner, and wherein the outer part (30) has at least one tab (40) on the first and/or the second end face (11, 12) that is freestanding in the direction of rotation about the axis of rotation (X) and projects beyond the respective end face (11, 12) of the inner part (20). Furthermore, the present invention relates to a gear (2) and a planetary gear (3).