Flexible Edge Bearing Ring Mitigates Edge Stress

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Solution Overview

Problem

Rolling-element bearings with line contact, such as tapered roller bearings, face issues with edge stresses due to off-center loads, which are exacerbated by the high precision and cost-intensive profiling required to distribute loads uniformly, and can lead to reduced load capacity and service life.

Innovation Solution

The introduction of a bearing ring with flexible edges, achieved through recesses in the edge surfaces or mounting surfaces, which can yield under pressure to mitigate edge stresses without the need for high-precision profiling, allowing for reduced material usage and cost-effective manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If convex profiling is provided on bearing rings and rolling elements to distribute loads uniformly, then edge stresses are reduced, but manufacturing precision requirements increase and production costs rise

Engineering Contradiction:

Improveedge stress resistanceVSAvoidprofile precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the physical state of the edge from rigid to flexible by introducing a flexible edge design. This allows the edge to adapt to load variations through elastic deformation, eliminating the need for high-precision convex profiling while maintaining uniform load distribution and reducing edge stresses.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The flexible edge introduces dynamic adaptability to the bearing structure. Instead of relying on statically precise convex profiles, the edge can dynamically adjust its position and contact pressure through elastic deformation, compensating for load variations and misalignments during operation.

Inventive Principle:

Principle #15Dynamics

2Reliability

If convex profiling is provided on bearing components to distribute loads uniformly, then load distribution improves, but processing and machining costs increase significantly

Engineering Contradiction:

Improveload distribution uniformityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the physical state of the edge from rigid to flexible, allowing it to adapt to load variations through elastic deformation. This eliminates the need for expensive high-precision convex profiling operations while maintaining uniform load distribution, significantly reducing manufacturing costs.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The flexible edge acts as a sacrificial element that deforms elastically to protect more critical bearing components. By allowing the edge to yield under extreme loads, the invention prevents catastrophic failure of rolling elements and raceways, reducing the need for expensive precision machining.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Duration of action of stationary object

If profiling is applied to bearing components to reduce edge stresses, then service life increases, but the rolling elements no longer abut on the running surfaces over their entire lengths, increasing pressure load

Engineering Contradiction:

Improvebearing service lifeVSAvoidpressure load on rolling elements

Core Design Contradiction:

Duration of action of stationary objectVSStress or pressure

Solution Approach 1:

The invention changes the physical state of the edge from rigid to flexible, allowing it to deform elastically under load. This maintains full-length contact between rolling elements and running surfaces, distributing pressure uniformly across the entire contact area while still protecting the bearing from edge stress damage, thereby extending service life without increasing pressure loads.

Inventive Principle:

Principle #35Parameter changes

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 flexible edge design effectively reduces edge stresses, enhances the service life of the bearing, and allows for uniform loading even under skewing conditions, while maintaining contact between the rolling elements and the running surface, thus improving the load capacity and reducing manufacturing costs.

Implementation Method 1

the bearing ring includes on at least one of its edge surfaces an edge which is designed to be flexible under pressure load. Due to this flexibility the edge stress can be counteracted without the need to provide the running surface of the bearing ring and/or of the rolling elements with a profile. The flexible edge can yield under pressure load so that the edge stresses can be reduced.

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS10247236B2Bearing ring

Publication Date: 2019.04.02 AB SKF SKF PATENT DEPARTMENT

AI summary

A rolling-element bearing assembly includes a support element and a bearing ring mounted on the support element. The bearing ring includes a substantially axial mounting surface in contact with the support element and a running surface configured to support a rolling element. The running surface has a first edge and a second edge axially spaced from the first edge and an axial width of the running surface is greater than an axial width of the mounting surface. The bearing ring includes a first cantilevered portion having a top surface, the top surface being a first end portion of the running surface, and a bottom surface facing the support element. The first cantilevered portion does not contact the support element and, extending axially from a junction of the support element and the mounting surface, a radial width of the first cantilevered portion decreases and then increases.