Aircraft Plain Bearing Lubrication Grooves for Oil Leakage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In aircraft turbomachines, plain bearings used in mechanical reducers face issues with oil leakage and excessive oil consumption due to axial movements of planet gears, which can lead to insufficient lubrication and potential seizure.
Innovation Solution
The implementation of a plain bearing design featuring a main lubrication groove and at least one secondary lubrication groove, both supplied by independent channels. The secondary grooves have a smaller passage cross-section, reducing oil leakage and maintaining sufficient pressure for lubrication during axial movements of the planet gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the length of the supply groove is reduced to prevent oil leakage during axial movements, then oil leakage is reduced, but lubrication effectiveness at the longitudinal ends of the bearing deteriorates
Solution Approach 1:
The lubrication system is segmented into a main supply groove and multiple secondary supply grooves positioned at different axial locations. Each groove is supplied by independent channels from the oil cavity, ensuring that lubrication is maintained at multiple positions along the bearing surface regardless of axial displacement of the planet gear.
Solution Approach 2:
The solution transitions from a single longitudinal groove to a multi-dimensional arrangement of grooves at different axial positions. This spatial distribution ensures that at least one groove remains covered and functional during axial movements, maintaining lubrication effectiveness without excessive oil leakage.
2Reliability
If a single main lubrication groove is used to ensure continuous lubrication, then lubrication coverage is improved, but oil leakage increases during axial movements of the planet gear
Solution Approach 1:
The single main lubrication groove is segmented into multiple smaller secondary grooves distributed along the axial direction. This segmentation reduces the exposed surface area of any single groove during axial movements, thereby reducing oil leakage while maintaining continuous lubrication coverage through the distributed arrangement.
Solution Approach 2:
Different regions of the bearing surface are provided with localized lubrication through independently supplied secondary grooves. This allows each local region to maintain adequate lubrication during axial movements while limiting the overall oil leakage through the distributed, smaller-scale groove configuration.
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 design effectively limits oil leakage and ensures continuous lubrication of the plain bearing, reducing the risk of seizure and maintaining the service life of the bearing.
Implementation Method 1
Oil is supplied to the internal cavity and is routed through a supply channel to a main lubrication groove formed on an external cylindrical surface of the body
Data Source
AI summary
A plain bearing for an aircraft turbomachine, the plain bearing having a tubular body including an outer cylindrical surface, an inner cavity designed to contain oil, a primary lubrification groove formed by a middle portion of the outer surface and a main channel for supplying the primary groove with oil, the plain bearing wherein the outer surface of the body further includes at least one secondary lubrification groove which is formed in an end portion of the outer surface and is independent of the primary groove, and in that the body further includes a secondary channel for supplying the or each secondary groove with oil