Aircraft Engine Front Attachment Axial Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The assembly of the front engine attachment in aircraft engines is complicated due to restricted axial space, especially with large-diameter hubs, making it difficult to introduce and secure the attachment components effectively.
Innovation Solution
A front engine attachment design featuring a shearing pin and main attachment body with axial retention means, including screws and barrel nuts, which allows for limited access assembly and direct force transmission, even with large hub diameters, utilizing a shearing pin oriented in the longitudinal direction and a main attachment body with a ball joint and protuberances for secure positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the front engine attachment is positioned close to the hub of the intermediate casing to improve force transmission, then the force transmission efficiency is improved, but the assembly complexity increases due to restricted axial space
Solution Approach 1:
The attachment components are nested within the limited axial space between the engine casing and the hub. The attachment body is positioned inside the axial gap, with the shearing pin passing through the hub and into the attachment body, creating a compact nested arrangement that achieves both close force transmission and feasible assembly
Solution Approach 2:
The shearing pin is oriented in the longitudinal direction (axial dimension) rather than radially, allowing the attachment to be secured from the axial direction where space is available, while still transmitting forces directly to the hub. This dimensional change enables assembly access while maintaining force transmission efficiency
2Strength
If a large-diameter hub is used to accommodate the intermediate casing, then the structural strength is improved, but the assembly difficulty increases due to restricted access space
Solution Approach 1:
The attachment system is segmented into distinct components: the attachment body, the shearing pin, and the barrel nut. This segmentation allows each component to be independently positioned and assembled through the limited axial space, with the shearing pin serving as a separate fastening element that can be inserted axially despite the large hub diameter
Solution Approach 2:
The shearing pin acts as an intermediary element that bridges the attachment body and the hub. It transmits forces from the attachment body to the hub while being insertable through the axial direction, solving the problem of connecting a large-diameter hub to the attachment in a space-constrained environment
Data Source
AI summary
For fitting of a front engine attachment of an engine assembly for an aircraft, a shearing pin is oriented in a longitudinal direction and is integral with a front closure rib of the strut housing and projects forward, a main attachment body is arranged axially opposite the intermediate casing hub, at the rear of the latter, the main attachment body having an orifice for accommodation of the shearing pin, an arrangement for securing the main attachment body on the engine, and an arrangement for axial retention of the main attachment body relative to the rib, the axial retention arrangement comprising first screws, the heads of which cooperate with the rib, as well as barrel nuts which cooperate with the screws, and are accommodated in the main attachment body.