Pulley Retaining Plug for Unitary Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Aftermarket pulley devices for vehicle tensioning idlers or runner rollers are not supplied as unitary assemblies, lacking the necessary screw, which complicates handling and installation.

Innovation Solution

A unitary pulley device design featuring a retaining plug that integrates bearing and shield retention, utilizing an interference fit and radial wedging for axial and radial retention, with error prevention markings for proper installation, and made from plastic or metal materials for ease of handling and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If pulley device is supplied without screw for aftermarket segment, then cost is reduced and flexibility is improved, but handling and transportation becomes more complex

Engineering Contradiction:
ImproveFlexibility in supply configurationVSAvoidHandling and transportation
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent combines multiple components (pulley, bearing, shields, and retaining means) into a single integrated unitary assembly. The retaining plug merges the function of retaining both shields and supporting the bearing into one component, eliminating the need for separate screws and simplifying handling while maintaining flexibility for aftermarket supply.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The retaining plug serves multiple functions simultaneously: it retains the first shield, retains the second shield, and supports the bearing. This multi-functional design reduces the number of separate components needed, improving ease of handling and transportation while maintaining manufacturing flexibility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If retaining plug uses interference fit, then retention reliability is improved, but assembly precision requirement increases

Engineering Contradiction:
ImproveRetention reliabilityVSAvoidAssembly precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent employs interference fit by designing the retaining plug with dimensional parameters that create an interference condition with the bearing bore and shield bores. This parameter change from clearance fit to interference fit improves retention reliability while the precise manufacturing of the plug ensures proper assembly.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If shields are mounted in axial contact with bearing, then sealing effectiveness is improved, but assembly complexity increases

Engineering Contradiction:
ImproveSealing effectivenessVSAvoidAssembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The retaining plug merges the function of positioning and retaining both shields in axial contact with the bearing into a single component. By integrating the retention function into the plug itself, the design achieves effective sealing while avoiding the need for additional retaining elements that would increase assembly complexity.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables a single, easily transportable pulley device assembly that simplifies installation by integrating bearing and shield retention, reducing errors and improving handling, while maintaining effective tensioning functionality.

Implementation Method 1

The axial retention of the plug with respect to the bearing is obtained by fitting. An interference fit may be provided.

Methodology Applied
Scientific EffectInterference fit: Friction

Implementation Method 2

The second retaining means may radially come into contact with the bore of the associated shield to axially retain said shield by radial wedging.

Methodology Applied
Scientific EffectRadial wedging: Wedge

Data Source

PatentEP3135957B1Pulley device with retaining plug
Publication Date: 2020.04.29 AB SKF SKF PATENT DEPARTMENT
  • EP3135957B1 patent drawingFigure 1
  • EP3135957B1 patent drawingFigure 2~3

AI summary

The pulley device comprises a bearing 14, a pulley 12 mounted on the bearing and two shields 16, 18 disposed axially on either side of the bearing. The device further comprises one retaining plug 20 mounted into a bore 30a of the bearing and a bore 16a, 18a of each shield. The retaining plug 20 is fitted at least in said bore of the bearing and cooperates by contact with the shields 16, 18 to retain said shields on said plug.