Bearing Housing Gutter Geometry for Low-Loss Lubricant Drainage
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Solution Overview
Problem
Industrial gas turbine engines face issues with lubricant flooding and foaming due to reduced momentum of used lubricant at the base of the bearing housing, caused by sharp directional changes and narrow passageways, leading to parasitic losses and inefficient lubrication.
Innovation Solution
A low loss drain configuration is implemented in the bearing housing, featuring a gutter with sloped floor portions that maintain downward momentum and facilitate the free flow of used lubricant into a gravity-fed drain, eliminating the need for a scavenge pump and reducing sharp directional changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If sharp directional changes and narrow passageways are used around the base of the bearing housing, then the structure is more compact, but the momentum of used lubricant is reduced causing it to collect at the base
Solution Approach 1:
The patent applies curved surfaces and smooth transitions in the passageway geometry instead of sharp angles. The bearing housing base features curved surfaces that guide lubricant flow smoothly into the drain, maintaining momentum while achieving compact dimensions. This resolves the contradiction by using curvature to preserve flow speed despite reduced volume.
2Reliability
If pumps are used to evacuate lubricant from the bearing compartment, then lubricant removal is ensured, but negative pressure is created increasing parasitic losses
Solution Approach 1:
The patent extracts and eliminates the pump component from the lubricant evacuation system. Instead of using a pump to create negative pressure, the design relies on gravity-fed drainage through optimally configured passageways and drain structures. This removes the energy-consuming component while maintaining reliable lubricant removal through passive gravitational flow.
Solution Approach 2:
The lubricant evacuation system is designed to be self-service through gravity-driven flow. The bearing housing and drain configuration automatically guide lubricant from the bearing compartment to the drain without external power input. The system uses the lubricant's own weight and optimized flow paths to achieve evacuation, eliminating the need for active pumping and associated energy losses.
3Productivity
If high oil flow rates are supplied to bearings for lubrication and cooling, then bearing performance is improved, but lubricant flooding and foaming occur if not evacuated timely
Solution Approach 1:
The patent implements preliminary action by designing the drain and passageway configuration in advance to match the high flow rates required for bearing lubrication. The gravity-fed drain system and optimized passageways are pre-configured to handle the expected lubricant volume, ensuring that as soon as high flow rates are supplied to the bearings, the evacuation system is already positioned and sized to prevent flooding and foaming.
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 effectively prevents lubricant flooding and foaming, ensuring efficient lubrication and cooling of turbine bearings even at high lubricant flow rates without the need for a scavenge pump, thereby minimizing parasitic losses.
Implementation Method 1
a drain disposed proximate a base of the gutter. The gutter includes a first sloped floor portion circumferentially adjacent to the drain... maintain downward momentum and facilitate the free flow of used lubricant into a gravity-fed drain
Implementation Method 2
After being supplied to the bearings, used lubricant is flung outward to an inner wall of the bearing housing
Data Source
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AI summary
A turbine module comprises a turbine shaft, a rotor assembly secured to the shaft, a bearing assembly rotatably supporting the turbine shaft, and a bearing housing containing the bearing assembly. The bearing housing includes a gutter at least partially circumscribing the bearing assembly, and a drain disposed proximate a base of the gutter. The gutter includes a first sloped floor portion circumferentially adjacent to the drain.