Angular Contact Ball Bearing with Oblique Raceways

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicle suspension thrust bearings with stamped sheet metal washers suffer from uneven stress distribution, leading to potential bearing failure, ball expulsion, and rapid wear due to multidirectional and asymmetrical stresses, as well as deformation of plastic support components.

Innovation Solution

An angular contact ball bearing design with oblique raceways and cylindrical stiffening skirts on washers, ensuring the raceways have a greater opening angle and tangents perpendicular to the axis of rotation, providing enhanced radial confinement and stiffness to manage centrifugal and centripetal forces, and reducing radial play and deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the thrust bearing uses stamped sheet metal washers with open raceways, then the manufacturing is simple and cost-effective, but the bearing rigidity and resistance to radial forces are insufficient

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidbearing rigidity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies curvature by designing the raceways as arcs of circles with specific opening angles (≥80° for lower raceway, ≥60° for upper raceway). This curvature enables the raceways to envelop the balls and provide radial confinement, transforming the flat sheet metal structure into a geometry that resists radial forces while maintaining manufacturing simplicity through stamping processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent adds dimensional features to the stamped washers by creating three-dimensional raceway profiles with specific opening angles and tangential configurations. The lower raceway is designed to be tangent to a plane perpendicular to the axis of rotation, adding a dimensional constraint that prevents ball expulsion while maintaining the simplicity of stamped sheet metal construction.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the raceway opening angle is increased to confine balls radially, then the radial confinement improves, but the bearing geometry becomes more complex

Engineering Contradiction:
Improveradial confinementVSAvoidraceway geometry complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent resolves the contradiction by optimizing specific geometric parameters: the lower raceway opening angle is set to ≥80° and the upper raceway opening angle to ≥60°, with specific tangential configurations. These parameter changes provide effective radial confinement while maintaining compatibility with standard stamping manufacturing processes, avoiding excessive geometric complexity.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If the bearing is undersized with respect to multidirectional stresses, then the device size is reduced, but ball expulsion and bearing failure occur

Engineering Contradiction:
Improvebearing sizeVSAvoidresistance to ball expulsion
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The curved raceway profiles with specific opening angles create an enveloping geometry that mechanically confines the balls in the radial direction. This curvature-based confinement mechanism prevents ball expulsion under multidirectional stresses without requiring an increase in overall bearing size, as the geometric design itself provides the retention function.

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Volume of moving object

If the plastic support components are undersized, then the assembly compactness improves, but deformation and contact between components occur

Engineering Contradiction:
Improveassembly compactnessVSAvoidcomponent deformation
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The curved, enveloping raceway geometry distributes contact stresses more evenly across the ball-bearing surfaces. This stress distribution reduces peak loads on the plastic support components, allowing them to maintain structural integrity and prevent deformation at compact sizes without requiring oversized components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP2488768B1Ball bearing and corresponding bump stop
Publication Date: 2016.12.07 NTN SNR ROULEMENTS
  • EP2488768B1 patent drawingFigure 1
  • EP2488768B1 patent drawingFigure 2
  • EP2488768B1 patent drawing

AI summary

The invention relates to a bearing for an angularly contacting bump stop, the washers of which consist of stamped sheet metal and have a surrounding geometry. The geometry of the bearing is such that, in every cutaway containing the geometrical axis of rotation (XX) of the bearing, the bottom bearing path forms a bottom circle arc (Cinf) defining a bottom axial curvature center (Oinf), and the top bearing path forms a top circle arc (Csup) defining a top axial curvature center (Osup), the bottom and top curvature centers being located on an angular geometrical axis (ZZ) that forms an angle of obliquity (F), of a value between 5° and 65°, with the geometrical axis of rotation (XX). More specifically, the bottom circle arc (Cinf) has two ends defining an opening angle (finf) of a value greater than or equal to 80° and a tangent located in a bottom plane (Pinf) perpendicular to the axis of rotation at a bottom tangent point (Iinf) defining, with the nearest bottom circle arc (Uinf) end, a portion of the bottom circle arc (Cinf) having an opening angle (?inf I) greater than or equal to 10°.