Sealed CV Joint Boot With Can-Constrained Expansion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing constant velocity joints face issues with excessive ballooning and contamination due to limited venting channels and the use of stiff materials that inhibit flexibility and fatigue performance, leading to potential rupture and contamination.

Innovation Solution

A constant velocity joint design featuring a flexible boot made of Shore 55A to 65A material, sealed by a can that maintains shape during expansion, and a clamp to secure the boot, eliminating the need for an o-ring seal, thereby preventing contamination and maintaining performance at high angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a flexible boot is used to accommodate pressure increases, then the boot can expand to relieve pressure, but excessive ballooning occurs which causes instabilities and decreased performance

Engineering Contradiction:

Improveboot flexibilityVSAvoidjoint performance stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent uses a flexible boot made from elastomeric material that can expand to accommodate pressure increases from heated air, while the boot's controlled flexibility prevents excessive ballooning. The boot acts as a flexible shell that manages pressure dynamics without compromising joint stability.

Inventive Principle:

Principle #30Flexible shells and thin films

2Strength

If a stiff, non-resilient elastomer material is used in the boot to prevent excessive ballooning, then resistance to high pressure is improved, but flexibility and fatigue performance decrease which inhibits the joint from withstanding high operating angles

Engineering Contradiction:

Improvepressure resistanceVSAvoidboot flexibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The patent specifies using elastomeric material with a shore hardness between 55A and 65A, which is softer than conventional stiff materials. This parameter change in material hardness provides both sufficient pressure resistance and the necessary flexibility for high-angle operation, resolving the contradiction between strength and adaptability.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If venting channels are formed in a flexible body of the vent valve, then pressure can be relieved in a controlled manner, but the channels are difficult to form with precision and are prone to plugging

Engineering Contradiction:

Improvepressure controlVSAvoidventing channel formation

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the vent valve assembly entirely from the CV joint design, eliminating the complex venting channel structure. Instead, the flexible boot itself manages pressure through controlled expansion, simplifying manufacturing by removing a difficult-to-produce component while maintaining pressure management functionality.

Inventive Principle:

Principle #2Taking out (Extraction)

4Adaptability or versatility

If the boot material is made softer to improve flexibility, then high-angle performance is improved, but the boot becomes more susceptible to excessive ballooning and rupture

Engineering Contradiction:

Improveboot flexibilityVSAvoidpressure resistance

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The patent identifies a specific shore hardness range of 55A to 65A for the elastomeric boot material. This optimized parameter range provides the optimal balance between flexibility for high-angle operation and sufficient strength to resist excessive ballooning and rupture, resolving the contradiction between adaptability and strength.

Inventive Principle:

Principle #35Parameter changes

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 design ensures consistent performance without boot rupture or contamination by allowing sufficient expansion and shape control, ensuring reliability and durability under high operating conditions.

Implementation Method 1

a boot comprised of a flexible material has an upper region connected to the outer race and a lower region connected to the second shaft. The boot is configured to seal the region between the outer race and the second shaft

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

A can overlies the boot and includes a shaping region for maintaining a shape of the boot along at least a portion of the boot as the boot expands and engages an inner surface of the can

Methodology Applied

Scientific EffectMechanical constraint: Mechanical Force

Data Source

PatentUS12510124B2Sealed constant velocity joint

Publication Date: 2025.12.30 NEAPCO INTELLECTUAL PROPERTY HOLDINGS LLC

AI summary

A constant velocity joint includes a first shaft extending along an axis and rotatable about the axis. An outer race is connected to and rotatable with the first shaft. The outer race defines a compartment. A rotatable second shaft terminates at an inner race in the compartment. The inner race is rotatable with the outer race and is pivotably connected to the outer race such that the inner race and second shaft are pivotable relative to the outer race. A boot comprised of a flexible material has an upper region connected to the outer race and a lower region connected to the second shaft. A can overlies the boot and includes a shaping region for maintaining a shape of the boot along at least a portion of the boot as the boot expands. The can and boot permit the joint to be fully sealed with optimized performance.