Turbine Test Bench Revolving Part Hub Double Pivot Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine test bench parts of revolution experience deformation at high rotational speeds, leading to undesirable loosening from the rotating shaft, which compromises sealing and prevents reaching the desired speed for testing turbines, especially in turboprop engines with operating speeds exceeding 18,000 revolutions per minute.
Innovation Solution
A part of revolution with a hub featuring five annular regions, where the second and fourth regions have lower thickness than the third and fifth, acting as double pivot deformation zones, decoupling the centrifugal-induced deformations and maintaining clamping at higher speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the part of revolution is rotated at high angular velocities, then the turbine testing capability is improved, but the part deforms and loosens from the rotating shaft
Solution Approach 1:
The hub is segmented into five distinct annular regions with varying thicknesses, creating localized deformation zones (second and fourth regions) that isolate centrifugal forces from the clamping interfaces. This segmentation allows different parts of the hub to perform different functions: some regions deform to absorb centrifugal effects while others maintain rigid clamping to the shaft.
Solution Approach 2:
Different annular regions of the hub are given different thicknesses to create localized properties. The second and fourth annular regions have reduced thickness to serve as deformation zones, while the first, third, and fifth regions maintain sufficient thickness for clamping functions. This local variation in geometry allows the hub to simultaneously deform where needed and maintain rigidity where clamping is required.
2Speed
If the body of the part deviates radially outwardly due to centrifugal effect, then rotation speed increases, but the hub loosens from the shaft
Solution Approach 1:
The harmful radial outward deviation of the entire hub is extracted and confined to specific annular regions (second and fourth regions). By creating localized deformation zones, the patent separates the necessary radial movement required for high-speed rotation from the clamping interfaces, allowing the hub to spin at high speeds while maintaining stable connection to the shaft.
Solution Approach 2:
The thickness parameter of the hub is varied across different annular regions. The second and fourth annular regions have reduced thickness compared to the first, third, and fifth regions. This parameter change creates zones of different stiffness, allowing controlled deformation in thinner regions while maintaining structural integrity and clamping in thicker regions.
3Speed
If the part is deformed by centrifugal effect at high speed, then the desired testing speed is reached, but sealing is compromised
Solution Approach 1:
The hub segmentation isolates deformation to specific annular regions away from the sealing interfaces. The fifth annular region, which interfaces with the sealing system, maintains sufficient thickness and rigidity to preserve sealing performance, while other regions deform to enable high-speed operation.
Solution Approach 2:
The sealing interface region (fifth annular region) is given different thickness characteristics compared to deformation zones. This local quality difference ensures that the sealing area remains stable and maintains proper geometry for effective sealing, while other parts of the hub deform to accommodate high-speed rotation.
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 design preserves clamping at significantly higher speeds than prior art, preventing unbalance and vibration, allowing for effective testing of turbines up to 30,000 revolutions per minute.
Implementation Method 1
the second annular region and the fourth annular region having a thickness lower than a thickness of the third and fifth annular regions, such that when the part of revolution is subjected to a centrifugal force, the second and fourth annular regions form favoured deformation zones behaving as a double pivot
Data Source
AI summary
The invention relates to a part of revolution (60) intended to be rotated, comprising a hub (62) intended to be tightly adjusted on a rotary shaft (24), and a body (14) extending radially outwards from an axial end of the hub. In order to increase the critical speed up to which the tightening can be retained, the hub (62) comprises three relatively thick annular regions (68, 66, 70) separated from one another by two relatively thin annular regions (64a, 64b), in such a way that when the part of revolution is subject to a centrifugal force (F), the two relatively thin annular regions (64a, 64b) form privileged deformation zones acting as a double pivot. Such a part can advantageously be used as a piston for balancing in a turbine test bench or in a turbomachine.