Bearing Cage Drain Paths for Lower Lubricant Heat Load
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine engines experience high bearing temperatures due to increased lubricant requirements for cooling, leading to excessive viscous heat generation and the need for larger lubricant lines and heat exchangers, which impacts heat load management.
Innovation Solution
Incorporation of lubricant drains in bearing assemblies to facilitate continuous lubricant flow in and out, reducing residence time and temperature, allowing for smaller lubricant lines and heat exchangers by using conduits and orifices in the bearing cage to control lubricant flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If increased lubricant requirements are used for cooling, then bearing temperature control is improved, but viscous heat generation increases and heat load management becomes more difficult
Solution Approach 1:
The patent extracts excess lubricant from the bearing assembly through dedicated drain paths formed in the cage structure. By removing unnecessary lubricant that would otherwise generate viscous heat, the system achieves better temperature control without increasing cooling lubricant requirements, thus resolving the contradiction between temperature control and viscous heat generation.
Solution Approach 2:
The patent changes the lubricant residence time parameter by implementing continuous drainage. This reduces the time lubricant remains in the bearing assembly, thereby reducing viscous heat generation while maintaining effective cooling, thus resolving the contradiction between temperature control and energy loss.
2Temperature
If larger lubricant lines and heat exchangers are used, then cooling capacity is improved, but device complexity and size increase
Solution Approach 1:
The patent extracts excess heat at the source by draining lubricant directly from the bearing assembly before it accumulates excessive heat. This eliminates the need for oversized heat exchangers and complex cooling systems, achieving effective cooling with simpler, more compact components.
3Temperature
If lubricant drains are added to bearing assemblies, then lubricant flow control is improved and temperature is reduced, but device complexity increases
Solution Approach 1:
The patent merges the lubricant drainage function with the existing cage structure by forming drain paths directly in the cage material. This integration eliminates separate drainage components and reduces overall device complexity while achieving effective temperature control through improved lubricant flow management.
Solution Approach 2:
The cage structure serves multiple functions: it maintains roller bearing spacing, guides lubricant flow, and provides drainage paths for excess lubricant removal. This multi-functionality reduces the need for additional components, maintaining simplicity while achieving temperature reduction.
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
Reduces bearing temperatures by 20-30%, enabling smaller lubricant lines and heat exchangers, and reduces viscous heat generation, allowing for increased shaft speeds and reduced lubricant supply.
Implementation Method 1
Turbine engines experience high bearing temperatures due to increased lubricant requirements for cooling, leading to excessive viscous heat generation
Data Source
AI summary
Lubricant draining bearing assemblies are disclosed. An example apparatus includes a first race, a second race, roller bearings positioned between the first race and the second race, and a cage positioned around the roller bearings between the first race and the second race, the cage including a first radial surface, a second radial surface, and an axial surface, the first radial surface facing the first race, the second radial surface facing the second race, the axial surface facing away from the roller bearings, the cage including at least one conduit extending between the first radial surface and at least one of the second radial surface or the axial surface, the conduit defining a flow path for a fluid out of a cavity between the first race, the roller bearings, and the cage.