Two-Piece Pulley Insert for Low-Force NVH Cover Retention

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Solution Overview

Problem

Existing noise reduction inserts for pulleys, such as those in internal combustion engines or electric motors, face challenges including high ergonomic forces during assembly, inaccurate installations, and insufficient retention due to degrading barbs, as well as a lack of clear installation feedback.

Innovation Solution

A two-piece noise reduction insert system where a first member is rotatable within the pulley and locks into place using a snap-fit arrangement, with a second member blocking further rotation to secure the first member, reducing assembly forces and providing visual confirmation of correct installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single-piece NVH cover with barbs is used, then retention in the pulley is achieved, but ergonomic forces during assembly become excessively high and barbs degrade

Engineering Contradiction:

Improveretention of NVH coverVSAvoidassembly difficulty

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The NVH cover is divided into two separate pieces: a first piece that is inserted into the pulley and a second piece that is inserted into the first piece. This segmentation eliminates the need for degradable barbs while distributing assembly forces across multiple components, reducing ergonomic strain on assembly workers.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second piece acts as an intermediary component that secures the first piece to the pulley without requiring direct barb engagement with the pulley. This intermediary structure provides reliable retention through a different mechanical mechanism that does not degrade during assembly.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If barbs are used for retention, then the NVH cover is secured to the pulley, but the barbs degrade during assembly resulting in insufficient retention

Engineering Contradiction:

Improveretention of NVH coverVSAvoidretention strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

By separating the retention function into a dedicated second piece with protrusions that engage with recesses in the pulley, the system eliminates the degradable barb structure while maintaining or enhancing retention strength through a more robust engagement mechanism.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If a single-piece NVH cover is used, then assembly is simpler, but there is no indication to the assembly worker when installation is complete

Engineering Contradiction:

Improveassembly processVSAvoidinstallation feedback

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The two-piece design provides inherent feedback to the assembly worker: the second piece can only be fully inserted into the first piece when the first piece is correctly positioned and rotated in the pulley. This mechanical interlocking provides clear tactile and visual confirmation of proper installation without complicating the overall assembly process.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS11434988B2Pulley insert

Publication Date: 2022.09.06 FORD GLOBAL TECH LLC

AI summary

Methods and systems are provided for a pulley insert. In one example, a pulley insert for a FEAD pulley comprises a first member insertable into a pulley such that the first member is rotatable within the pulley, the first member comprising a cavity for receipt of a second member; and a second member insertable into the cavity of the first member such that, when the first member is inserted into a pulley and the second member is inserted into the cavity of the first member, the second member prevents rotation of the first member relative to the pulley.