Link-Plate Chain Retainer Pin Positioning for CVT Durability
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Solution Overview
Problem
Existing link-plate chain designs for continuously variable transmissions face issues with retainer pin detachment due to rocker pin rocking, particularly because retainer pins attached equidistantly from link plates repeatedly contact link plates, leading to weld peeling and potential detachment.
Innovation Solution
The link-plate chain design positions retainer pins of inside rocker pins more outwardly in the transverse direction than those of outside rocker pins, preventing contact with link plates during rocking and thus avoiding weld peeling and detachment, while maintaining a simple structure without additional components or machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If retainer pins are attached equidistantly from link plates, then the structure is simple and easy to manufacture, but the retainer pins repeatedly contact link plates during rocker pin rocking, causing weld peeling and potential detachment
Solution Approach 1:
The patent applies local quality by differentiating the attachment positions of retainer pins based on their location. Outer rocker pins have retainer pins attached at a first distance from the link plate, while inner rocker pins have retainer pins attached at a second distance that is greater than the first distance. This localized differentiation prevents repeated contact and weld peeling for inner rocker pins while maintaining simple equidistant attachment for outer rocker pins, thus resolving the contradiction between ease of manufacture and reliability.
2Reliability
If retainer pins are positioned to prevent contact during rocking, then reliability improves, but structural complexity increases
Solution Approach 1:
The patent uses local quality to prevent repeated contact only where necessary - specifically for inner rocker pins that experience rocking motion. The attachment position differentiation (first distance for outer pins, second distance for inner pins) is minimal and localized, avoiding the need for complex structural modifications, position fixing members, or additional components. This resolves the contradiction by achieving reliability enhancement with minimal increase in device complexity.
3Reliability
If additional components or structural modifications are added to prevent retainer pin detachment, then reliability improves, but the structure becomes more complex
Solution Approach 1:
The patent applies parameter changes by modifying the attachment position parameter (distance from link plate) rather than adding components or structural modifications. The first distance for outer rocker pins and the second distance for inner rocker pins are different parameters that prevent repeated contact. This approach improves reliability while maintaining simple structure without position fixing members, projections, notches, or other additional components.
Data Source
AI summary
A link-plate chain for a continuously variable transmission, having a plurality of link plates interconnected in a chain circumferential direction and a chain transverse direction to be wound around an input pulley and an output pulley, by a plurality of rocker pins inserted to extend in the traverse direction through pin holes formed in the link plates, and attached with retainer pins for preventing detachment of the link plates from the rocker pins at ends in the transverse direction of the rocker pins, wherein: the retainer pins of the inside rocker pins sandwiched between the outer side rocker pins in the longitudinal direction among the rocker pins inserted through the link plates located at outermost ends in the transverse direction are configured to be attached more outward in the transverse direction than the retainer pins of the front and rear end side rocker pins.