Split Ring Attachment for Turbine Duct Mass Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing attachment methods for ancillary routing ducts on aircraft turbine machines with open rotor contra-rotating propellers result in increased dimensions and mass due to the need for a large outside diameter, which affects propulsion efficiency and requires additional thickness for threaded connections, leading to increased diameters of surrounding elements.
Innovation Solution
A split ring with internal projections and a tapered radial loading surface is used for attachment to the annular installation portion of the attachment case, allowing for a smaller duct diameter without excess thickness, utilizing axial loading means to secure the ring in place, thereby reducing the mass and dimensions of surrounding elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If threaded attachment means (nut and thread) are used on the duct, then mechanical attachment strength is improved, but the outside diameter of the duct increases due to the thread and nut stop requiring additional thickness
Solution Approach 1:
A split ring is introduced as an intermediary component between the duct and the attachment case. The split ring carries the threaded attachment means (nut and thread) on its outer circumference, while the duct itself remains thin-walled without additional thickness for threading. This mediator allows strong mechanical attachment while maintaining a compact duct diameter.
Solution Approach 2:
The attachment system is segmented into separate functional components: the duct body remains simple and thin, while the attachment functionality is moved to the split ring component. This segmentation allows each component to be optimized independently - the duct for minimal diameter and the split ring for attachment strength.
2Reliability
If the duct outside diameter is increased to accommodate threaded attachment means, then attachment reliability is improved, but the dimensions and mass of surrounding elements (such as reduction gear components) increase
Solution Approach 1:
The split ring acts as a mediator that isolates the duct from the attachment case, allowing the attachment mechanism to be positioned away from the duct's critical diameter. This ensures reliable attachment through the split ring's robust threading while preventing the duct's outside diameter from increasing, thereby avoiding the need to increase the size and mass of surrounding elements like the reduction gear.
3Productivity
If the duct diameter is reduced to improve propulsion efficiency, then engine diameter and hub ratio are optimized, but the attachment means require additional thickness that increases the duct diameter
Solution Approach 1:
The duct system is segmented into the thin-walled duct proper and the separate split ring attachment component. This allows the duct diameter to be minimized for optimal propulsion efficiency, while the attachment functionality resides in the split ring which does not constrain the duct's outside diameter.
Solution Approach 2:
The split ring serves as an intermediary that provides the attachment interface between the duct and attachment case without requiring the duct itself to have increased thickness. This enables the duct to maintain its minimal diameter for propulsion efficiency while still achieving reliable mechanical attachment through the split ring's threading mechanism.
Data Source
AI summary
An assembly for an aircraft turbine machine including a receiver for a pair of open rotor contra-rotating propellers, the assembly including a duct, ancillaries routed inside the duct, an attachment case, attachment device of the duct on an annular installation portion of the case. The attachment device in an assembled configuration include a split ring fitted with internal projections housed inside orifices in the duct; a radial loading surface of the ring made on the portion the surface being tapered and narrowing along a first axial direction, and being in contact with a peripheral surface of the complementary shaped tapered split ring; device of axially loading the ring along the first direction, the device being blocked in the axial direction on the portion.