Turbojet Suspension via Strut Assembly to Reduce Casing Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional coupling methods for turbojet engines with front fans cause distortions and wear due to force transmission, leading to performance deterioration and reduced service life, especially in engines with high bypass ratios and larger diameter ratios between fan and main flow casings.
Innovation Solution
A suspension system for turbojet engines that uses radial arms and a structural strut assembly to transmit forces without deforming cylindrical casings, with a shear pin for axial forces and flexible or rigid attachments to manage thrust and moments, reducing the need for force acceptance at the front attachment and minimizing longitudinal flexing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional coupling methods are used to attach the engine to the mast, then the engine can be suspended and forces can be transmitted, but the casings undergo distortions and wear due to torque-induced flexing
Solution Approach 1:
The patent introduces an intermediary rigid beam structure that connects the engine casing to the mast, serving as a mediator to transmit forces without allowing direct torque-induced flexing of the engine casing itself. The beam acts as a rigid link that decouples the harmful flexing from the engine components.
Solution Approach 2:
The suspension system is segmented into distinct functional components: the engine casing, the rigid beam intermediary, and the mast attachment points. This segmentation allows each component to perform its specific function while isolating the engine casing from harmful forces.
2Power
If the diameter ratio between fan casing and main flow casing is increased for high bypass ratio engines, then engine power increases, but the distortions and wear increase due to greater torque amplitudes
Solution Approach 1:
The rigid beam serves as a mediator that isolates the high-power engine from the mast, transmitting forces without allowing torque-induced flexing to affect the engine casing. This intermediary structure enables high power output while preventing the harmful effects of torque variations.
3Adaptability or versatility
If link arms and clevis type attachments are used to transmit forces, then forces in three directions can be transmitted, but the attachment points form zones of small extent causing local distortions
Solution Approach 1:
The patent transitions from point-based attachments (clevis types) to a distributed beam structure that spreads the attachment points along the length of the beam. This dimensional change from points to a linear distribution allows force transmission in multiple directions while eliminating the concentration of stress at single attachment zones.
Data Source
AI summary
A turbojet suspended from an aircraft mast is disclosed. The turbojet includes a front fan, an intermediate casing downstream of the fan with an outer shroud and a hub connected together by radial arms, and an exhaust casing with an outer shroud, the two casings being aligned on one and the same axis XX. The mast includes a structural strut assembly of elongated shape. The strut assembly is attached upstream rigidly to the outer shroud of the intermediate casing by a front attachment including a device for transmitting the axial and lateral forces and downstream by a rear attachment to the exhaust casing.