CVP Carrier Slot Wall Liners for Skew-Shifting Wear Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mechanical contact and interaction between components in a continuously variable planetary (CVP) system lead to material wear and tear, causing deterioration in the range of transmission ratios and shortening the lifespan of the system, particularly due to wear on slot walls and contamination of traction fluid.
Innovation Solution
A protective layer, made from metallic or wear-resistant materials like steel, is affixed to the slot walls of carriers to mitigate mechanical abrasion, using attachment features such as tabs and pockets to secure the layer without affecting the mechanical structure or properties of the carrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If carriers are rotated relative to each other to enable skew-shifting transmission ratio control, then transmission ratio range is improved, but mechanical wear on slot walls increases
Solution Approach 1:
A protective layer is introduced as an intermediary between the slot wall and the planet axle/end cap. This protective layer absorbs the mechanical wear and interaction forces, preventing direct contact between the moving components and the carrier slot wall. The protective layer can be a coating, liner, or separate component that is easier to replace and protects the underlying carrier structure.
Solution Approach 2:
The protective layer is applied to the slot wall before the wear problem occurs. This preliminary protective measure ensures that when skew-shifting operation begins, the slot wall is already protected. The protective layer can be applied through coating processes, bonding, or pre-installation of protective inserts during carrier manufacturing.
2Adaptability or versatility
If planet axles and end caps interact with carrier slots during skew-shifting, then transmission ratio control is improved, but material wear and tear increases
Solution Approach 1:
The protective layer serves as a mediator between the planet axle/end cap and the carrier slot. It absorbs the mechanical interaction forces and wear, extending the lifespan of the moving components. The protective layer can be designed to be replaceable, allowing the expensive planet assemblies to last longer while only the protective layer needs periodic replacement.
Solution Approach 2:
The protective layer is designed as a sacrificial component that can be easily replaced. Instead of replacing entire carriers or planet assemblies when wear occurs, only the protective layer needs to be replaced. This approach is more economical and extends the overall system lifespan by protecting the expensive permanent components.
3Reliability
If mechanical wear occurs on slot walls, then transmission ratio range deteriorates, but adding protective layers increases device complexity
Solution Approach 1:
The protective layer is applied locally only to the slot wall areas that experience wear, rather than protecting the entire carrier. This can be done through selective coating, localized bonding, or installing protective inserts only in the critical contact zones. This approach maintains transmission ratio stability while minimizing the increase in device complexity.
Solution Approach 2:
The protective layer can be segmented into multiple sections or applied as separate protective inserts for different parts of the slot wall. This segmentation allows for easier installation, replacement, and optimization of protective coverage in high-wear areas only, reducing overall complexity compared to a full-coverage protective system.
Data Source
AI summary
A continuous variable planetary (CVP) system comprises a C2 carrier having a pattern of slots, the slots having one or more slot walls; a C1 carrier, at least one of the C2 carrier or C1 carrier being rotatable relative to the other; at least three planetary assemblies coupled between the C2 carrier and the C1 carrier, each planetary assembly including a planet, a planet axle, and an end cap on at least one end of the planet axle, the end cap disposed within the slot, rotation of C2 carrier relative to the C1 carrier inducing a skew condition in the planet axle and thereby inducing a tilt condition on the planet axle; and a protective layer affixed against at least one of the one or more slot walls, the protective layer including one or more protective layer attachment features configured to attach to one or more slot wall attachment features.