CVT Pulley Sheave Alignment for Wide-Range Power Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing continuously variable transmissions require precise construction to maintain alignment and reduce wear, which is not effectively achieved during use, leading to inefficiencies in transmitting driving force across a wide range of operational conditions.
Innovation Solution
Incorporating alignment means that allow the movable sheaves to jointly move axially under the influence of the transmission element's force, while maintaining the operative radius, using a combination of spring and damping forces, and a pressure chamber to adjust the pulley's radius, ensuring consistent alignment and reduced wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If precise construction is used to maintain alignment, then wear is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies the dynamics principle by making the sheaves axially movable rather than fixed. The sheaves can move axially to self-align with the transmission element, allowing the system to adapt to misalignment dynamically during operation. This resolves the contradiction by replacing precise static construction with dynamic adjustment capability.
Solution Approach 2:
The alignment means enable the sheaves to self-align with the transmission element automatically during operation. The system uses its own operational forces to maintain proper alignment without requiring external adjustment mechanisms or extremely precise manufacturing tolerances, thus reducing manufacturing complexity while maintaining reliability.
2Adaptability or versatility
If sheaves are made axially movable to adjust operative diameter, then transmission range is increased, but alignment stability deteriorates
Solution Approach 1:
The patent introduces alignment means as an intermediary mechanism between the movable sheaves and the transmission element. This intermediary component actively maintains alignment stability despite the sheaves' axial movability, allowing the system to achieve both wide transmission range and stable alignment simultaneously.
Solution Approach 2:
The system changes the operational parameters by allowing axial position of sheaves to vary dynamically. The alignment means ensure that despite these parameter changes, the critical alignment parameter remains stable, enabling both adaptability and stability.
3Ease of operation
If transmission element is allowed to move axially, then transmission flexibility is improved, but contact alignment deteriorates
Solution Approach 1:
The alignment means enable the transmission system to self-correct axial misalignment automatically. As the transmission element moves axially, the alignment means guide the sheaves to maintain proper contact alignment, providing both flexibility and precision without requiring external intervention or extremely tight manufacturing tolerances.
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 solution maintains a high degree of alignment between the transmission element and pulley, allowing for efficient transfer of driving force across a large transmission range, reducing wear and enhancing the reliability of the transmission system.
Implementation Method 1
said first and second adjustable sheaves being held under spring tension against a spring force from a spring means
Implementation Method 2
said first and second adjustable sheaves being held under damping against a damping force from a damping means
Data Source
AI summary
A continuously variable transmission including a first pulley means, a second pulley means and an elongate, flexible endless transmission element that is passed over both the first pulley means and the second pulley means, wherein the first pulley means include two sheaves which are adjustable in an axial direction of the first rotation axis line, and an adjusting means for moving the two adjustable sheaves toward and away from each other in the axial direction for setting an operative radius of the first pulley means at which the transmission element is passed over the first pulley means, wherein the first pulley means is provided with alignment means for causing the two movable sheaves to jointly move additionally in the axial direction of the first rotation axis under the influence of a force exerted in axial direction on the first pulley means by the transmission element while maintaining the operative radius.