Center Vent Tube Support Device for Turbofan Engine
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing center vent tube support device in turbofan engines experiences asymmetric deformation due to the C-shaped ring and sleeve design, leading to uneven contact surfaces and potential abnormal load transmission or abrasion.
Innovation Solution
A center vent tube support device comprising an annular sleeve, a pair of ring segments, and an annular nut, where the ring segments have cylindrical and conical surfaces to ensure even contact with the main shaft, preventing deformation and maintaining uniform contact pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a C-shaped ring and sleeve design is used in the center vent tube support device, then the device can be installed inside the main shaft, but asymmetric deformation occurs leading to uneven contact surfaces and potential abnormal load transmission or abrasion
Solution Approach 1:
The ring is divided into two separate semi-circular segments that can be independently manufactured and then assembled together inside the main shaft. This segmentation allows each segment to be manufactured separately with proper tolerances, and when assembled, they form a complete circular support structure that contacts the main shaft uniformly at multiple points, preventing asymmetric deformation and ensuring even load distribution.
2Ease of manufacture
If the ring is formed as a single C-shaped component, then manufacturing is simplified, but asymmetric deformation occurs under radial pressure causing uneven contact and potential abrasion
Solution Approach 1:
The ring is segmented into two independent semi-circular components that can be manufactured separately and assembled inside the main shaft. This segmentation prevents asymmetric deformation because each segment can independently conform to the main shaft's inner surface, creating multiple contact points that distribute radial pressure evenly, thereby preventing the concentration of stresses that lead to abrasion.
Solution Approach 2:
The ring segments are designed with a curved cross-section that matches the circular geometry of the main shaft's inner surface. This curvature ensures that when the segments are assembled and pressed against the main shaft, they make contact along an arc rather than at discrete points, distributing the contact pressure evenly and preventing localized abrasion.
3Device complexity
If a single ring structure is used, then the device is simpler, but it deforms asymmetrically under radial pressure leading to uneven contact pressure distribution
Solution Approach 1:
The ring is divided into two independent semi-circular segments that can be assembled inside the main shaft. This segmentation allows each segment to independently respond to radial pressure by deforming symmetrically toward the center, maintaining a stable circular configuration. The segmentation prevents the asymmetric deformation that would occur in a single C-shaped ring because each segment has its own symmetric geometry relative to the main shaft's center.
Solution Approach 2:
The two ring segments are positioned symmetrically opposite each other inside the main shaft, creating a balanced structure where each segment counterbalances the other. This symmetric arrangement ensures that radial pressure is distributed evenly around the circumference, preventing asymmetric deformation and maintaining stable contact pressure distribution. The segments act as counterweights to each other, maintaining equilibrium under load.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution prevents abnormal load transmission and abrasion by ensuring even contact between the ring segments and the main shaft, enhancing the durability and stability of the support mechanism.
Implementation Method 1
an outer surface of the sleeve or the nut includes a pressurizing surface formed as a conical surface; each of the ring segments includes a bearing surface formed as a part of a conical surface having a vertex angle equal to that of the conical surface forming the pressurizing surface
Implementation Method 2
each of the ring segments includes a supporting surface formed as a part of a cylindrical surface having a diameter equal to an inner diameter of the main shaft in a portion where the device is to be installed
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a center vent tube support device that can prevent transmission of abnormal load between members and prevent abrasion of a contact surface. A device (1) includes: an annular sleeve (10) having an inner surface that comes into contact with an outer surface of a center vent tube (CVT); a ring (20) formed of a pair of segments (22) and placed between the sleeve and a main shaft (LS); and an annular nut (30) for fixing the ring to the sleeve. An outer surface of the sleeve or the nut includes a pressurizing surface formed as a conical surface. Each of the ring segments includes a supporting surface formed as a cylindrical surface having a diameter equal to an inner diameter of the main shaft in a portion where the device is to be installed, a bearing surface formed as a conical surface having a vertex angle equal to that of the conical surface forming the pressurizing surface, a pair of side surfaces, and a pair of end faces formed as planes each spaced from a plane including the axis. The supporting surface and the bearing surface are formed of an outer surface of a rim portion of the ring segment and an inner surface of a bore portion of the ring segment, respectively. A diameter of a circle circumscribing a projected shape of the device in a direction perpendicular to the end face is smaller than an inner diameter of a smallest-diameter portion of the main shaft.