Sliding Bearing Pivot Structure for Gear Tooth Alignment

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Solution Overview

Problem

Conventional pivots in epicyclic gear trains experience misalignments due to non-identical deformations between upstream and downstream spans, caused by tangential and radial displacements, which affect the reliability and efficiency of the bearing and gear train.

Innovation Solution

The pivot design incorporates a plurality of orifices on a specific angular sector between 5° and 330°, providing increased flexibility and balancing deformations, allowing for better alignment of teeth with the axis of the gear train, which can be achieved through a simple drilling operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the pivot is made rigid to maintain structural strength, then strength is improved, but misalignment of teeth occurs due to non-identical deformations between upstream and downstream spans

Engineering Contradiction:
Improvestructural strengthVSAvoidalignment precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The pivot incorporates orifices only in a specific angular sector (5° to 330°) rather than uniformly throughout, creating localized flexibility in the region where misalignment occurs. This allows the pivot to have different mechanical properties in different regions: rigid where strength is needed and flexible where alignment compensation is required.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the physical structure of the pivot by introducing orifices, which alter the local stiffness and flexibility parameters. The orifices modify the deformation characteristics of the pivot in the specific angular sector, enabling it to compensate for non-identical deformations between upstream and downstream spans while maintaining overall structural integrity.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the pivot is made flexible to accommodate deformations, then alignment is improved, but structural strength decreases

Engineering Contradiction:
Improvealignment precisionVSAvoidstructural strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The orifices are strategically positioned in a specific angular sector rather than being distributed uniformly, creating localized flexibility only where needed for alignment compensation. The rest of the pivot structure maintains its full strength and rigidity, avoiding overall weakening.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The pivot is effectively segmented into different functional zones: the angular sector with orifices provides flexibility for alignment, while the remaining portions maintain structural strength. This segmentation allows simultaneous optimization of both strength and alignment properties in different regions.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If orifices are added to the pivot to increase flexibility, then alignment of teeth is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvealignment precisionVSAvoidstructural complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention modifies the pivot structure by introducing orifices with specific dimensional parameters (angular sector 5° to 330°, specific diameters and positions). These parameter changes achieve the desired flexibility and alignment improvement while maintaining a relatively simple overall structure that can be manufactured using conventional processes.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If orifices are made larger or more numerous to increase flexibility, then alignment is improved, but mass of the pivot increases

Engineering Contradiction:
Improvealignment precisionVSAvoidpivot mass
Core Design Contradiction:
Manufacturing precisionVSWeight of moving object

Solution Approach 1:

The orifices are confined to a specific angular sector (5° to 330°) rather than being distributed throughout the entire pivot circumference. This localized approach provides the necessary flexibility for alignment while removing material only where needed, thereby minimizing the increase in pivot mass.

Inventive Principle:
Principle #3Local quality

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

This design enhances the alignment of teeth in the epicyclic gear train, reducing mass and improving the reliability and efficiency of the bearing by balancing deformations between upstream and downstream sides.

Implementation Method 1

making orifices on a given angular sector, more flexibility can be provided at this angular sector of the pivot compared to the rest of the pivot, which allows greater local deformation of the pivot

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3682138B1Pivot for a sliding bearing
Publication Date: 2021.10.27 SAFRAN TRANSMISSION SYST
  • EP3682138B1 patent drawingFigure 1~2
  • EP3682138B1 patent drawingFigure 3~4
  • EP3682138B1 patent drawingFigure 5~6C

AI summary

The invention relates to a pivot (60) for a sliding bearing of a planetary gear train, comprising an annular wall delimiting an axial passage and comprising a first (52c) and a second annular groove opening axially in opposite directions and each delimited by two internal (52a) and external (52b) coaxial annular branches formed at the axial ends of the annular wall. According to the invention, the pivot comprises a plurality of first orifices (60a) opening at a first end into the first annular groove (52c) and at a second opposite end into the second annular groove, said orifices being produced on an angular sector of between 5° and 330°.