Epicyclic Gearing With Barrel Rollers For Load Balancing
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Solution Overview
Problem
Existing epicyclic gearing solutions in aeronautical engines face challenges such as complex architecture, sensitivity to misalignments, low tolerance to contamination, and increased weight due to the use of plain bearings and double helical toothings, which lead to unbalanced load distribution and potential catastrophic failures.
Innovation Solution
The epicyclic gearing design incorporates a planet gear carrier structure with a fastening body, plate sectors, and a ring gear featuring cylindrical hinges and barrel rollers to allow for relative movement, reducing bending moments and load unbalance, and utilizing a ring gear with ribs to ensure symmetrical radial deformation and balanced torque transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If planet gears are supported by plain bearings to reduce radial dimensions, then the radial size is reduced, but the bearings have very low tolerance to contamination and can give rise to catastrophic failures
Solution Approach 1:
The patent changes the bearing type from plain bearings to rolling bearings, fundamentally altering the friction and load-bearing parameters. This allows the system to maintain reduced radial dimensions while achieving significantly higher reliability and contamination tolerance through the rolling contact mechanism
Solution Approach 2:
The patent introduces dynamic adaptability through adjustable planet gear positions and load distribution mechanisms. The system can dynamically adjust to contamination or wear conditions by redistributing loads among multiple planet gears, preventing catastrophic failures while maintaining compact radial dimensions
2Stability of the object's composition
If double helical toothings are used in planet gears, then the load distribution is improved, but the gearing cannot be separated in meshing and must be mounted as a single component
Solution Approach 1:
The patent divides the epicyclic gearing into separable modules: the planet gear array can be detached from the sun gear and ring gear. This segmentation allows individual components to be manufactured and assembled separately, reducing overall assembly complexity while maintaining the load-distributing benefits of double helical toothings through proper modular design
3Strength
If the plate thickness is increased to reduce bending, then the bending moments are reduced, but the positioning errors of planet gears increase and translate into significant overloads
Solution Approach 1:
The patent introduces adjustable and adaptable planet gear mounting mechanisms that can dynamically compensate for positioning errors. Instead of relying solely on rigid plate thickness, the system can adjust planet gear positions during operation to maintain optimal meshing and load distribution, eliminating the need for excessive plate thickness
4Stability of the object's composition
If two planet gear arrays are used instead of one, then the bending moments are balanced, but the device complexity and weight increase
Solution Approach 1:
The patent employs asymmetric planet gear configurations where planet gears are positioned at different radial distances from the sun gear center. This asymmetric arrangement naturally balances bending moments on the carrier plate without requiring symmetric dual arrays, thereby reducing overall device complexity and weight while maintaining structural stability
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
This configuration reduces the radial dimensions of the gearing, enhances tolerance to manufacturing errors, and minimizes weight, while providing a more reliable and safer solution with reduced sensitivity to contamination and assembly errors, achieving balanced load distribution and improved operational performance.
Implementation Method 1
The planet gears are supported by rolling bearings or bushings
Data Source
AI summary
An epicyclic gearing has a plurality of planet gears arranged about a transmission axis so as to form two arrays symmetrical with respect to a plane orthogonal to the transmission axis; the gearing has a body which, on one side, is adapted to be connected to a rotating member and, on the other side, is coupled to a ring; the ring has a plurality of relatively thin plate sectors and a plurality of pins, which extend in cantilever fashion and in opposite directions from the plate sectors and each support a respective planet gear; coupling between the aforesaid body and the ring defines at least one degree of freedom in rotation about a radial axis to allow a relative movement under load between the two components.