Gas Turbine Lubrication System for Negative Gravity Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine components, such as gears and bearings, face damage due to interrupted lubrication during negative gravity conditions and windmilling, as the main pump fails to supply adequate lubricating liquid, leading to non-lubricated operation.
Innovation Solution
A pump system comprising a main pump, an auxiliary pump, an auxiliary reservoir, a sump, and a valve system that selectively directs lubricating liquid from the main pump, auxiliary reservoir, or sump to the bearings based on engine operating conditions, ensuring continuous lubrication through sensing mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single main pump and reservoir system is used, then the device complexity is reduced, but the reliability of lubrication supply deteriorates under negative gravity and windmilling conditions
Solution Approach 1:
The pump system is segmented into two independent subsystems: a main pump/main reservoir system for normal operation, and an auxiliary pump/auxiliary reservoir system for abnormal conditions. This segmentation allows each subsystem to be optimized for its specific operating mode, ensuring reliable lubrication supply across all conditions without requiring an overly complex integrated system.
Solution Approach 2:
The system changes operational parameters by switching between different pump-reservoir configurations based on operating conditions. The valve system enables parameter changes in fluid flow paths, allowing the system to adapt from main pump operation to auxiliary pump operation, and between different reservoir sources, thereby maintaining reliability across varying gravity and speed conditions.
2Reliability
If an auxiliary pump and auxiliary reservoir are added to ensure continuous lubrication, then the reliability of lubrication supply is improved, but the device complexity and weight increase
Solution Approach 1:
The auxiliary pump and auxiliary reservoir are designed with multi-functionality to reduce overall system complexity. The auxiliary reservoir serves dual purposes: supplying lubricant to the auxiliary pump during abnormal conditions and receiving excess lubricant from the main reservoir during normal operation. This universal design allows the same components to serve multiple functions across different operating modes, reducing the need for additional specialized components.
Solution Approach 2:
The system merges the auxiliary reservoir's functions by making it both a supply source for the auxiliary pump and a receiving container for excess lubricant from the main system. This combining of functions into a single component reduces the number of separate parts needed, thereby reducing device complexity while maintaining reliability.
3Quantity of substance
If the auxiliary reservoir is continuously filled from the main reservoir, then the availability of lubricant for auxiliary pump is improved, but the loss of lubricant from the main reservoir deteriorates
Solution Approach 1:
The filling of the auxiliary reservoir from the main reservoir occurs periodically rather than continuously. The one-way valve allows lubricant transfer only when the main reservoir level is sufficiently high, creating a periodic transfer action. This periodic action ensures the auxiliary reservoir is replenished when needed while preventing excessive or continuous drainage from the main reservoir, thereby balancing lubricant availability with conservation.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A pump system (50) for lubricating a bearing (54) in a gear system (36) of a gas turbine engine (10) includes a main pump (66), an auxiliary pump (44), an auxiliary reservoir (58), a sump (48), and a valve system (60, 62). The main pump is fluidically connected to the bearing through a main supply passage (78, 80). The auxiliary pump is fluidically connected to the bearing through an auxiliary supply passage (76, 80). The valve system transfers lubricating liquid from the main pump to the bearing under a first set of engine operating conditions. The valve system transfers lubricating liquid from the auxiliary reservoir to the sump and from the sump through the auxiliary pump to the bearing under a second set of engine operating conditions. The valve system transfers lubricating liquid from the auxiliary reservoir through the auxiliary pump, bypassing the sump, to the bearing under a third set of engine operating conditions.