Multi-lip Bearing Seal Adapting to Misalignment

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Solution Overview

Problem

Existing bearing seal assemblies for agricultural applications suffer from high friction and reduced sealing effectiveness due to eccentricity and misalignment issues, leading to early wear and inefficient sealing performance, even under contaminated conditions.

Innovation Solution

A bearing seal assembly featuring a multi-lip resilient annular gasket made of elastomeric material, anchored by a sheet metal insert with radially inward disc and conical portions, providing a labyrinth seal and maintaining contact with the inner ring surface to adapt to misalignment while minimizing friction and maintaining sealing efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a multi-lip seal with three squat and tough lips is used, then sealing barrier is provided, but friction against the inner rotating ring increases causing early wear and energy waste

Engineering Contradiction:
Improvesealing effectivenessVSAvoidfriction
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the geometric parameters of the sealing lips from squat and tough to thin and elongate. This parameter change reduces the contact area and stiffness of the lips, thereby reducing friction against the inner rotating ring while maintaining sealing effectiveness through increased flexibility and adaptability to misalignment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs thin and elongate sealing lips that act as flexible elements. These flexible lips can deform and adapt to misalignment between bearing rings, maintaining continuous sliding contact and sealing performance without the high friction associated with rigid squat lips

Inventive Principle:
Principle #30Flexible shells and thin films

2Stability of the object's composition

If the shroud comes out of alignment, then sealing structure is maintained, but the three squat and tough lips will not provide the same sealing action

Engineering Contradiction:
Improvestructural integrityVSAvoidsealing performance consistency
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent transitions from static squat lips to dynamic thin and elongate lips that can flex and adapt. The flexible lips dynamically adjust their position and contact pressure in response to misalignment, ensuring consistent sealing performance regardless of alignment variations between bearing rings

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameters of the lips (thin and elongate versus squat and tough) to enable adaptability. This parameter change allows the sealing structure to maintain reliability under misalignment conditions while preserving structural integrity through the flexible nature of the elongate lips

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the slinger and shroud change positions due to misalignment of supports, then bearing unit operates, but sealing action does not perform properly

Engineering Contradiction:
Improvebearing operationVSAvoidsealing performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent uses flexible thin and elongate sealing lips that can accommodate position changes of the slinger and shroud. These flexible lips maintain continuous sliding contact with the inner ring even when supports become misaligned, ensuring proper sealing action is maintained during normal bearing operation despite support misalignment

Inventive Principle:
Principle #30Flexible shells and thin films

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 solution ensures reliable sealing performance under misalignment and contamination, with reduced wear and energy loss, as the flexible lips adjust contact pressure to maintain continuous sliding contact and prevent contaminants from entering the bearing unit.

Implementation Method 1

a multi-lip resilient annular gasket made of elastomeric material... the flexible lips adjust contact pressure to maintain continuous sliding contact

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2435719B1A bearing seal assembly, particularly for use in agricultural applications
Publication Date: 2015.04.15 AB SKF SKF PATENT DEPARTMENT
  • EP2435719B1 patent drawingFigure 1~2

AI summary

The bearing seal assembly (50) includes a metal shield (70) and a resilient multi-lip sealing gasket (60) secured to the metal shield. The metal shield is supported in use by an outer ring (20) of a rolling contact bearing and includes a diagonally extending central portion (72). The sealing gasket (60) provides a number of contacting lips (62-64) facing an inner ring of the rolling contact bearing. A first, main contacting lip (66) exerts a first radial load on the inner ring. A second contacting lip (62) extends from the first lip (66) and exerts a second radial load on the inner ring lower than the first radial load. A third contacting lip (64) is on the opposite side of the second lip (62) with respect to the first lip (66) and exerts a third radial load on the inner ring lower than the first radial load but greater than the second radial load.