Reusable Pulley Dust Cap With Elastomer Seal and Tool Recess

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Solution Overview

Problem

Existing dust caps for pulley assemblies are either ineffective in preventing contaminants due to design flaws, difficult to install, or not reusable, leading to damage and increased costs during installation and shipping.

Innovation Solution

A reusable dust cap design featuring a plastic or metallic body with an elastomeric portion and a tool-receiving engagement feature, allowing for easy installation and removal without deformation, and a sealing bead to prevent contaminants, which can be over-molded or mechanically bonded for enhanced sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a metallic dust cap is used to substantially prevent contaminants from entering the bearing, then sealing effectiveness is improved, but installation force requirement increases and the cap may damage the bearing race during removal

Engineering Contradiction:
Improvesealing effectivenessVSAvoidinstallation force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The dust cap combines a metallic body (for structural strength and sealing effectiveness) with an elastomeric material layer (for reduced installation force and bearing protection). This composite structure allows the cap to maintain its sealing function while requiring less installation force and preventing bearing race damage during removal, as the elastomeric material provides compliance and cushioning.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the physical parameters of the dust cap by adding an elastomeric material layer that alters the mechanical properties. This layer reduces the hardness and increases the compliance of the cap, enabling it to be installed with lower force and removed without damaging the bearing race, while still maintaining effective sealing against contaminants.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If an over-molded dust cap with rubber seal is used to ease installation, then ease of operation is improved, but the cap becomes non-reusable and vulnerable to shipping damage

Engineering Contradiction:
Improveease of installationVSAvoidreusability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The dust cap uses a composite structure with a rigid metallic body and an elastomeric material layer. The metallic body maintains structural integrity and resistance to shipping damage, while the elastomeric layer provides ease of installation through its compliance. Unlike fully over-molded rubber caps, this composite design prevents the puncturing issue during removal, enabling reusability while maintaining ease of operation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention applies different material properties to different parts of the dust cap: the metallic body provides structural strength and durability for shipping and handling, while the elastomeric material layer provides compliance and ease of installation. This localized application of material properties allows the cap to be both easy to install and reusable without compromising either characteristic.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If a plastic dust cap with cutouts is used to reduce installation force, then ease of operation is improved, but contaminant prevention effectiveness deteriorates

Engineering Contradiction:
Improveease of installationVSAvoidcontaminant prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The dust cap combines a metallic body (for sealing effectiveness) with an elastomeric material layer (for ease of installation). The elastomeric layer acts as a compliant seal that prevents contaminants from entering through the interface between the cap and bearing, eliminating the need for cutouts while maintaining ease of installation through the material's compliance and ability to deform during installation and removal.

Inventive Principle:
Principle #40Composite materials

4Reliability

If a metallic dust cap is used to prevent contaminants, then sealing effectiveness is improved, but the cap cannot be removed without damaging the bearing race

Engineering Contradiction:
Improvesealing effectivenessVSAvoidease of removal
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The dust cap uses a composite structure with a metallic body (for sealing effectiveness) and an elastomeric material layer (for ease of removal). The elastomeric layer acts as a protective cushion between the metallic cap and the bearing race, allowing the cap to be removed without concentrating stress on the bearing race. This enables maintenance and reuse while maintaining effective sealing during operation.

Inventive Principle:
Principle #40Composite materials

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 dust cap effectively seals pulley components from contaminants, is easy to install and remove multiple times without damage, and can be shipped with the pulley assembly, reducing costs and installation force, while maintaining structural integrity.

Implementation Method 1

an elastomeric material that is configured to sealingly engage the bearing outer race

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

an engagement feature formed in the dust cap body that allows a tool to engage the dust cap for installing and removing the dust cap from the pulley assembly

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3137780B1Reusable dust cap for a pulley assembly
Publication Date: 2021.06.09 DAYCO IP HOLDINGS LLC
  • EP3137780B1 patent drawingFigure 1
  • EP3137780B1 patent drawingFigure 2
  • EP3137780B1 patent drawingFigure 3

AI summary

A dust cap for sealing engagement with an opening of a member is disclosed. The dust cap is removable from the opening of the member by a tool. The dust cap includes a body and an elastomeric portion. The body defines an outer perimeter, an inner surface, an outer surface, and a recess disposed along the outer surface. The recess is shaped to receive a portion of the tool. The elastomeric portion is located around the outer perimeter of the body. The elastomeric portion is sealingly engageable with the opening of the body member.