Articulation Stop for CVJ Boot Protection

Solution Overview

Problem

Constant velocity joints in automotive vehicles face damage due to excessive angular manipulation during propeller shaft installation, which can pinch and damage the flexible boot, leading to reduced boot life and potential failure.

Innovation Solution

A joint apparatus with an angular range of motion limiting device that restricts articulation, featuring a spider with trunnions and roller assemblies within a tulip structure, preventing the boot from being pinched by limiting the articulation of the shaft relative to the tulip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the joint is designed to allow free articulation for installation flexibility, then ease of operation is improved, but the boot may be pinched and damaged during manipulation

Engineering Contradiction:

Improveinstallation flexibilityVSAvoidboot integrity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

A limiting device is introduced as an intermediary component between the shaft and the boot. This device selectively restricts articulation of the shaft relative to the tulip, preventing excessive manipulation that would pinch the boot while still allowing sufficient movement for installation. The limiting device acts as a mediator that protects the boot from damage during normal operation and installation procedures.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the joint allows maximum articulation range for operational versatility, then adaptability is improved, but components such as the boot are exposed to damaging configurations

Engineering Contradiction:

Improvearticulation rangeVSAvoidboot damage risk

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The limiting device applies preliminary anti-action by preemptively restricting articulation before damaging configurations can occur. During installation and normal operation, the limiting device prevents the shaft from articulating beyond safe angles, thereby preventing the boot from being pinched between the shaft and tulip. This preliminary protective action eliminates the harmful effect before it can manifest.

Inventive Principle:

Principle #9Preliminary anti-action

3Device complexity

If the joint structure is simplified without protection mechanisms, then device complexity is reduced, but the boot becomes vulnerable to damage during manipulation

Engineering Contradiction:

Improvejoint structureVSAvoidboot lifespan

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

A limiting device is introduced as an intermediary component between the shaft and the boot. This device selectively restricts articulation of the shaft relative to the tulip, preventing excessive manipulation that would pinch the boot while still allowing sufficient movement for installation. The limiting device acts as a mediator that protects the boot from damage during normal operation and installation procedures.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8475286B2Articulation stop

Publication Date: 2013.07.02 GKN DRIVELINE NORTH AMERICA INC

AI summary

A joint apparatus includes an outer joint portion having an opening end, an outer joint axis, and an outer joint inside surface defining, at least in part, an internal vault. The joint apparatus also includes an inner joint portion including a spider interposed within the outer joint portion and a shaft extending through the opening end. The spider includes a trunnion. The trunnion is at least partially interposed within the vault. The shaft defines a shaft axis. The inner joint portion includes an angular range of motion limiting device that selectively restricts the articulation of the shaft relative to the outer joint to prevent the shaft from contacting the outer joint.