Planet Carrier Assembly Through Sidewall Opening Without Strength Loss

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing planet carriers for epicyclic gearboxes face challenges in maintaining structural integrity and efficient assembly, particularly when loading gears through a sidewall, which can complicate the process and reduce the carrier's structural integrity.

Innovation Solution

A planet carrier design featuring a cover plate that can be attached to the carrier body to partially or fully close openings, allowing gears to be inserted through a strategically sized opening that matches the gear dimensions, ensuring proper alignment and meshing without compromising structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the planet carrier is made as a single piece with large openings for gear insertion, then the ease of assembly is improved, but the structural integrity of the carrier body deteriorates

Engineering Contradiction:
Improveease of assemblyVSAvoidstructural integrity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The planet carrier is divided into two main segments: a carrier body and a separate cover plate. The carrier body contains openings for gear insertion, while the cover plate closes these openings. This segmentation allows the carrier body to have sufficient structural integrity while still enabling gear assembly through the openings.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cover plate acts as an intermediary element between the carrier body and the external environment. It provides a closing surface for the openings in the carrier body, maintaining structural integrity while allowing gears to be assembled through the openings before the cover plate is attached.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the opening size is increased to accommodate all gears, then the ease of operation is improved, but the structural integrity of the carrier body deteriorates

Engineering Contradiction:
Improveease of gear insertionVSAvoidstructural integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

By separating the carrier body from the cover plate, the design allows the carrier body to have optimally sized openings for gear insertion without compromising overall structural integrity. The cover plate compensates for the openings, maintaining strength while enabling ease of operation.

Inventive Principle:
Principle #1Segmentation

3Strength

If the planet carrier uses multiple pieces joined together, then the structural integrity is improved, but the device complexity increases

Engineering Contradiction:
Improvestructural integrityVSAvoidcomplexity of assembly
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The planet carrier is segmented into the carrier body and cover plate, which are joined together. This segmentation provides structural integrity while keeping the assembly process relatively simple: gears are inserted through openings in the carrier body, then the cover plate is attached to close the openings.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3667048B1Planet carrier and method of assembling of a planet carrier
Publication Date: 2022.06.15 ROLLS ROYCE PLC
  • EP3667048B1 patent drawingFigure 1~2
  • EP3667048B1 patent drawingFigure 3
  • EP3667048B1 patent drawingFigure 4

AI summary

Disclosed herein is a planet carrier (34) for an epicyclic gearbox (30), the planet carrier (34) comprising: a single piece carrier body arranged to support a plurality of gears (28, 32) of the epicyclic gearbox (30); and an opening (41) in a wall of the carrier body; wherein: in a cross-section of the carrier body in a plane that is orthogonal to the longitudinal axis of the carrier body and at a longitudinal position along the carrier body that does not comprise the opening (41), the carrier body is substantially annular; and the opening (41) is arranged such that the gears (28, 32) that the carrier body is arranged to support can be passed entirely through the opening (41).