Toric-Drive CVT Skew Limiter for Fixed Skew Angle Control
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Solution Overview
Problem
Conventional roller position control mechanisms in Toric-drive Continuously Variable Transmissions (CVT) face challenges in maintaining consistent skew angles as they change tilt angles, leading to potential imbalances and inefficiencies in speed ratio adjustments.
Innovation Solution
A skew limiter is introduced, featuring shaped projections that limit the skew angle to a fixed maximum regardless of the tilt angle, preventing further pivoting of the inner control ring and maintaining consistent roller orientation across varying tilt conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional roller position control mechanisms are used to change tilt angles, then speed ratio adjustments can be made, but consistent skew angle maintenance becomes difficult leading to imbalances
Solution Approach 1:
The control ring is designed to pivot dynamically about the longitudinal axis, allowing the skew angle to adjust automatically in response to tilt angle changes. This dynamic adjustment mechanism ensures that the skew angle remains consistent throughout the range of motion, resolving the contradiction between adaptability and stability.
Solution Approach 2:
The control ring acts as a feedback mechanism that automatically adjusts the skew angle based on the tilt angle position. As the rollers change tilt angle, the control ring pivots to provide the corresponding skew angle adjustment, creating a self-regulating system that maintains consistent skew angles without external intervention.
2Adaptability or versatility
If the control ring is allowed to pivot freely about the longitudinal axis, then skew angle adjustment is possible, but excessive skewing occurs leading to inefficiencies
Solution Approach 1:
The skew angle limiters are positioned asymmetrically on the control ring, creating a mechanical constraint that prevents excessive skewing in one direction while allowing necessary adjustment in the other direction. This asymmetric design ensures reliable roller orientation by limiting the range of skew angles to optimal values.
Solution Approach 2:
The skew angle limiters are pre-positioned to counteract potential excessive skewing before it occurs. By placing these limiters on the control ring, the system proactively prevents harmful skew angles while still allowing necessary adjustments, thereby maintaining reliability and preventing inefficiencies.
3Ease of operation
If skew angle is allowed to vary with tilt angle, then roller position flexibility is improved, but balanced roller orientation is compromised
Solution Approach 1:
The control ring provides dynamic coupling between tilt angle and skew angle adjustments. As the rollers move through their range of tilt angles, the control ring automatically pivots to provide the corresponding skew angle changes, maintaining balanced roller orientation throughout the entire range of motion while preserving position flexibility.
Solution Approach 2:
The control ring serves multiple functions simultaneously: it adjusts skew angles, limits excessive skewing, and maintains balanced roller orientation across the entire range of tilt angles. This multi-functional design resolves the contradiction by providing both flexibility and stability through a single integrated mechanism.
Data Source
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AI summary
A skew limiter for a toric-drive CVT is described herein. The skew limiter proposes a shaped piece that limits the skew angle to a known angle notwithstanding the tilt angle of the rollers.