Aircraft Propeller Vane Retaining Ring for Hub Failure Safety
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Solution Overview
Problem
Existing aircraft turbine engine propellers with open rotor designs face a significant risk of vane loss in case of hub failure, as they lack adequate radial direction retention mechanisms.
Innovation Solution
The implementation of a vane retaining ring structure cladded around the hub, equipped with a tightening device and angular sectors, provides additional radial retention and a 'Fail Safe' function by allowing two structures to operate independently in case of failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hub with accommodating ports is used to retain vanes radially outwardly, then the propeller structure is simple and easy to manufacture, but the reliability is reduced because there is a risk of vane loss in case of hub failure
Solution Approach 1:
The patent applies beforehand cushioning by introducing a retaining ring structure that provides redundant vane retention capability before hub failure occurs. The retaining ring is positioned to catch vanes radially outwardly if the hub fails, preventing vane loss. This preparatory safety mechanism ensures that even if the primary retention system (hub) fails, the secondary system (retaining ring) is already in place to prevent catastrophic consequences.
Solution Approach 2:
The patent applies segmentation by dividing the retention function into two separate components: the hub with accommodating ports for normal operation, and the retaining ring as an independent safety component. This segmentation allows each component to be optimized independently - the hub for ease of manufacture and the retaining ring for reliability - while together they provide both simplicity and safety.
2Reliability
If a retaining ring structure is added around the hub to provide redundant retention, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The patent applies flexible shells and thin films by using a retaining ring with a cross-section designed to be flexible in the radial direction. This flexibility allows the retaining ring to deform and adapt to the hub geometry during installation and operation, simplifying the assembly process while maintaining its retention function. The thin-walled structure provides sufficient strength for vane retention without adding excessive complexity.
Solution Approach 2:
The retaining ring structure serves as a beforehand cushioning mechanism that is pre-installed around the hub. It provides a safety net that is already in position before any failure occurs, eliminating the need for complex active retention systems while significantly improving reliability through passive redundancy.
3Reliability
If the retaining ring structure is made tight against the hub, then the radial retention is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by designing the retaining ring with specific geometric parameters that enable self-adjustment. The cross-sectional shape and material properties are selected to allow the ring to deform elastically under tightening forces, accommodating variations in hub dimensions without requiring extremely tight manufacturing tolerances. This parameter optimization balances retention effectiveness with manufacturability.
Solution Approach 2:
The flexible retaining ring structure can deform to accommodate manufacturing tolerances and hub dimensional variations. This flexibility reduces the stringency of manufacturing precision requirements while still maintaining effective tight contact with the hub for reliable radial retention of vanes.
Data Source
AI summary
A propeller for an aircraft turbine engine comprising a plurality of vanes as well as a hub having a plurality of accommodating ports receiving the bases of said vanes, each vane base being rotatably mounted in its associated accommodating port. The propeller also has at least one vane retaining ring structure in the radial direction outwardly from the hub, being cladded around the latter.