Asymmetrical Roller Profile for Even Load Distribution in Bearings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rolling bearing profiles are symmetrical and fail to effectively distribute loads when they are not centrally applied, leading to edge wear, high surface pressures, and premature failure.

Innovation Solution

A rolling element with a logarithmic profile that transitions from a flat to a steep shape based on expected loads, using different logarithmic coefficients for areas under central and extreme loads, ensuring even load distribution and extended service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a symmetrical profile is used for rolling elements, then the design is simple and manufacturing is easier, but the load distribution becomes uneven when loads are not centrally applied, leading to edge wear and high surface pressures

Engineering Contradiction:
Improveease of manufactureVSAvoidreliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies asymmetry by introducing a profile asymmetry parameter ε that creates different curvature radii on opposite sides of the rolling element. The first curvature radius r1 and second curvature radius r2 are made different through the asymmetric logarithmic profile, allowing the rolling element to adapt to non-central loads and distribute pressure more evenly across the contact surface, thereby improving reliability without significantly complicating manufacturing

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent implements local quality by varying the curvature radius locally across different regions of the rolling element profile. The logarithmic profile function with asymmetric coefficients creates locally optimized curvature radii (r1 and r2) that are tailored to specific load conditions, allowing each region of the profile to handle loads optimally while maintaining overall structural integrity

Inventive Principle:
Principle #3Local quality

2Duration of action of moving object

If a flat profile is used for rolling elements, then the service life under uniform central load is improved, but edge wear occurs under extreme loads or tilting conditions

Engineering Contradiction:
Improveservice lifeVSAvoidedge wear
Core Design Contradiction:
Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by creating a profile that can dynamically adapt its effective geometry based on load conditions. The asymmetric logarithmic profile with position-dependent curvature radii allows the contact area to dynamically adjust during operation - maintaining a flatter effective profile under central loads for extended service life, while automatically providing edge support under extreme loads or tilting conditions to prevent edge wear

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the curvature radius parameter throughout the profile. The logarithmic profile function with asymmetric coefficients creates a continuous variation in curvature radius from the center to the edges, allowing the profile to transition between flat and steep characteristics depending on the local region and load application point, thereby preventing both excessive wear under central loads and edge wear under extreme loads

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3837450B1Rolling element having an asymmetrical roller profile, rolling element bearing, wind turbine and method for geometrically dimensioning rolling elements
Publication Date: 2023.10.04 ROTHE ERDE GMBH
  • EP3837450B1 patent drawingFigure 1a~1e
  • EP3837450B1 patent drawingFigure 2~3
  • EP3837450B1 patent drawingFigure 4

AI summary

The invention relates to a rolling element (1) for use in rolling element bearings (10), in particular in large rolling element bearings. In the unloaded state, the rolling element (1) has a logarithmic profile (1'). The profile (1') satisfies the profile function indicated as (I) in the drawing, wherein Dwe corresponds to the maximum diameter of the rolling element (1) and Lwe corresponds to the effective length of the rolling element (1), C1 is a first logarithm coefficient, C2 is a second logarithm coefficient, xgrenz is a transition constant, and C1 and C2 have different values.