Turbine Engine Lubrication Using a Spring-Driven Auxiliary Pump
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine engines face challenges in maintaining lubricant supply to rotating components during windmilling conditions, particularly for journal bearings, which can lead to failure due to inadequate lubrication, especially when the primary lubrication system fails or operates at low speeds.
Innovation Solution
An auxiliary lubrication system powered by a strain energy storage system, utilizing a torsional spring to store energy during normal operation and release it to operate an auxiliary pump when the turbine engine is shut down or windmilling, ensuring continuous lubricant supply to rotating components regardless of propulsor direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the primary lubrication system is used during normal operation, then lubricant supply is sufficient, but the system fails to provide lubrication during windmilling conditions
Solution Approach 1:
The lubrication system is divided into two independent subsystems: a primary lubrication system that operates during normal engine operation, and an auxiliary lubrication system that operates during windmilling conditions. This segmentation allows each subsystem to be optimized for its specific operational context, ensuring reliable lubrication across all operating conditions without requiring the primary system to adapt to unsuitable low-speed conditions.
Solution Approach 2:
The auxiliary lubrication system is pre-configured with a pump and lubricant supply line connected to the sump, ready to activate when windmilling conditions occur. The system includes pre-positioned components such as the auxiliary pump, lubricant supply line, and connection to rotating components, enabling immediate lubrication delivery when needed without requiring system reconfiguration during the transition to windmilling mode.
2Reliability
If the auxiliary lubrication system operates independently of propulsor shaft rotation, then lubrication is provided during windmilling, but system complexity increases
Solution Approach 1:
The auxiliary lubrication system merges with the existing primary lubrication system by utilizing the same sump and lubricant supply infrastructure. The auxiliary pump draws lubricant from the common sump and delivers it through a supply line that connects to the same rotating components serviced by the primary system. This merging approach allows the auxiliary system to provide independent windmilling lubrication while sharing common resources, thereby reducing overall system complexity compared to a completely separate lubrication system.
3Reliability
If lubrication is maintained during windmilling, then bearing failure is prevented, but additional lubricant consumption occurs
Solution Approach 1:
The auxiliary lubrication system provides partial lubrication action specifically targeted at preventing bearing failure during windmilling conditions, rather than full lubrication of all rotating components. The system activates only when windmilling conditions are detected, providing just enough lubrication to protect critical bearing surfaces from failure during this specific operational mode, thereby minimizing unnecessary lubricant consumption during normal operation while still achieving the reliability goal.
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
The system ensures consistent lubrication to rotating components during normal operation and windmilling, preventing bearing failure and reducing system complexity by independent operation from propulsor shaft rotation.
Implementation Method 1
a strain energy storage system comprising a spring drivingly coupled to the auxiliary pump shaft, wherein the spring stores strain energy during normal operation of the turbine engine and releases the strain energy when the propulsor is windmilling
Data Source
AI summary
A lubrication system for a turbine engine. The turbine engine includes a propulsor and one or more rotating components. The lubrication system includes a sump, a primary lubrication system, an auxiliary lubrication system, and a strain energy storage system. The sump stores lubricant therein. The primary lubrication system supplies the lubricant from the sump to the one or more rotating components during normal operation of the turbine engine. The auxiliary lubrication system includes an auxiliary pump including an auxiliary pump shaft. The strain energy storage system includes a spring drivingly coupled to the auxiliary pump shaft. The spring stores strain energy during normal operation of the turbine engine and releases the strain energy when the propulsor is windmilling to rotate the auxiliary pump shaft to power the auxiliary pump such that the auxiliary pump pumps the lubricant from the sump to the one or more rotating components.