Split Planet Carrier Cage for Aircraft Reducer Satellite Assembly

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Solution Overview

Problem

The assembly of satellites in the cage of a speed reducer for an aircraft turbomachine can be challenging due to the rigid connection of the cage, which makes it difficult to transmit loads and maintain proper positioning of satellite guide levels.

Innovation Solution

A school rack design featuring a cage with two rooms, where one room includes axial protrusions with free ends that are fixed to the other room using screws, allowing for clamping and precise alignment of the cage parts, thereby facilitating load transmission and satellite positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the cage is made as a single rigid piece, then the structural strength is improved, but the ease of manufacture deteriorates due to difficulty in assembling satellites

Engineering Contradiction:
Improvestructural strengthVSAvoidease of assembly
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The cage is divided into two separate parts: a first part comprising one wall and the bridges, and a second part comprising the other wall. This segmentation allows satellites to be assembled into the first part before the two parts are joined together, significantly easing the assembly process while maintaining structural integrity through the rigid connection of the two parts

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the cage is divided into multiple parts, then the ease of manufacture is improved, but the device complexity increases due to additional connection requirements

Engineering Contradiction:
Improveease of assemblyVSAvoiddevice complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The cage is divided into two parts that are connected through the bridges. The bridges serve as the connection element between the two parts, providing a straightforward joining mechanism that reduces complexity compared to more elaborate connection systems

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bridges serve multiple functions: they connect the two parts of the cage, provide mounting locations for satellites, and maintain the structural rigidity of the assembly. This multi-functionality reduces the need for additional separate components

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Force

If the cage parts are rigidly connected, then the load transmission is improved, but the ease of operation deteriorates due to difficulty in positioning satellites

Engineering Contradiction:
Improveload transmissionVSAvoidease of satellite positioning
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The cage is segmented into two parts that can be assembled separately with satellites positioned in the first part. After assembly, the two parts are rigidly connected through the bridges, ensuring proper load transmission while maintaining the positioning accuracy achieved during the assembly phase

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4336068B1Planet carrier for a speed reducer of an aircraft turbine engine
Publication Date: 2025.05.14 SAFRAN TRANSMISSION SYST
  • EP4336068B1 patent drawingFigure 1
  • EP4336068B1 patent drawingFigure 2
  • EP4336068B1 patent drawingFigure 3

AI summary

A satellite carrier (213) for a speed reducer (10) of an aircraft turbomachine (1), comprising: - a cage carrier (222), - a cage (220), characterized in that the cage (220) comprises two parts (220a, 220b): - a first part (220a) comprising a wall (236) and brackets (240a1, 240b1), these brackets (240a1, 240b1) projecting axially from a face (236a) of this wall (236) and comprising first axial ends (293) connected to this face (236a) and second free axial ends (294), and - a second part (220b) comprising another wall (238), this other wall (238) comprising a face (238a) on which the free ends (294) of the bridges (240a1, 240b1), and in that the two parts (236, 238) of the cage (220) are fixed together by fastening means (299).