Driven Clutch Helix Assembly With Sealed Rollers for CVT Wear
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Solution Overview
Problem
Continuously variable transmissions (CVTs) in recreational vehicles face challenges with component packaging, debris fouling, and wear, which affect performance and require frequent maintenance.
Innovation Solution
The CVT system incorporates a driven clutch with a helix assembly featuring five rollers, a nested design, and anti-wear coatings to enhance structural integrity, reduce debris intrusion, and improve load sharing, while using dynamic seals to maintain lubrication and reduce wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional CVT components are used, then the transmission can operate, but components accumulate debris that fouls internal mechanisms and wears components, requiring frequent maintenance
Solution Approach 1:
The patent converts the harmful effect of debris accumulation by implementing a sealed helix assembly that prevents debris entry, and uses wear-resistant coatings to transform the wear problem into a controlled surface protection system. The dynamic seals convert the harmful infiltration of contaminants into a protected internal environment.
Solution Approach 2:
The patent introduces dynamic seals as intermediary elements between the external environment and the helix assembly internal mechanisms. These seals act as mediators that block debris while allowing the necessary mechanical motion to occur, protecting the rollers and helix from contamination.
2Volume of moving object
If CVT components are packaged to fit recreational vehicles, then space is utilized, but packaging of components becomes challenging due to space constraints
Solution Approach 1:
The patent implements a nested design where the helix assembly is positioned within the driven clutch housing, and rollers are nested within the helix structure. This nesting arrangement maximizes space utilization within the constrained volume of the driven clutch, allowing complex mechanisms to fit within limited space while maintaining functional integrity.
3Reliability
If the helix assembly uses traditional sealing, then lubrication can be maintained, but seals wear and allow debris intrusion over time
Solution Approach 1:
The patent implements dynamic seals that automatically compensate for wear through their elastic properties. The seals maintain continuous contact with the rotating components, self-adjusting to maintain the sealing barrier without external intervention. This self-service mechanism extends seal service life while maintaining lubrication integrity.
4Volume of moving object
If the driven clutch uses a compact design, then packaging is improved, but component wear increases due to higher contact pressures
Solution Approach 1:
The patent applies wear-resistant coatings to the helix and roller surfaces, creating a composite structure where the base material provides structural integrity while the coating layer provides enhanced wear resistance. This allows compact design with high contact pressures without sacrificing component life, as the coating protects against wear at the high-stress contact interfaces.
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 solution enhances CVT durability, reduces maintenance needs, and improves performance by evenly distributing load and reducing wear, allowing for higher operational speeds and extended service intervals.
Implementation Method 1
The spring extends from a proximal end coupled to a proximal portion of the helix to a distal end configured to contact at least a portion of the distal portion of the movable sheave
Implementation Method 2
The sidewall defines a plurality of roller tracks. Each respective roller track is configured to receive in a sliding engagement the roller of a respective roller assembly
Data Source
Figure 1A
Figure 1B
Figure 1C~1D
AI summary
A driven unit helix assembly for a continuously variable transmission including a roller sleeve (240), a helix (244), a spring (248), and a helix sleeve (250). The roller sleeve is configured to coupled to a movable sheave and axially translate along a post. A plurality of roller assemblies radially extend from the roller sleeve and travel within roller tracks of the helix, such that the roller sleeve and helix define coaxial components coupled an axial sliding engagement. The spring extends from a proximal end coupled to a proximal portion of the helix to a distal end configured to contact at least a portion of the distal portion of the movable sheave, thereby urging the movable sheave in the distal direction. The helix sleeve extends circumferentially around the helix and is configured to retain a fluid in the helix assembly.