Gear Pump Lubrication Valves for Lower Parasitic Loss
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Solution Overview
Problem
Gear pumps for fuel delivery in aircraft engines are oversized for low-load conditions, leading to parasitic losses and reduced operational efficiency, and they lack redundancy in lubrication, which shortens their in-service life and requires frequent overhauls.
Innovation Solution
A gear pump system with pressure relief valves that automatically shut off lubrication flow at low pressures and include redundant pathways to ensure lubrication at high loads, allowing for smaller pump designs and extended operational life, and can be retrofitted into existing systems without extensive redesign.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pump is oversized for low-load conditions, then sufficient fuel pressure and lubrication are provided at all operating speeds, but parasitic losses increase and operational efficiency decreases
Solution Approach 1:
The patent implements a dynamic lubrication system where flow paths selectively open and close based on pump pressure conditions. At high pressures, lubrication flow paths are open to provide adequate bearing lubrication. At low pressures, the same flow paths close to prevent parasitic losses. This dynamic adaptation allows the pump to maintain reliability across varying operating conditions without continuous energy waste.
2Reliability
If continuous lubrication flow is provided to the bearing shaft interface, then bearing lubrication is maintained, but parasitic losses increase and pump flow capacity decreases
Solution Approach 1:
The patent employs periodic action by making lubrication flow intermittent rather than continuous. Flow paths to the bearing shaft interface open when pump pressure exceeds a threshold and close when pressure drops below the threshold. This periodic activation ensures bearing lubrication is provided only when necessary, maintaining reliability while preserving pump flow capacity during low-pressure operations.
3Reliability
If the pump is designed for high-pressure operations, then sufficient lubrication is provided at high speeds, but the pump requires extensive redesign to optimize low-load efficiency
Solution Approach 1:
The patent applies universality by designing flow paths that serve multiple functions: they act as lubrication channels when open and as flow restrictors when closed. The same structural elements (flow paths, check valves, orifices) handle both high-pressure lubrication delivery and low-pressure flow management, eliminating the need for separate systems and avoiding extensive redesign while achieving efficiency across operating conditions.
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 reduces parasitic losses, increases pump flow capacity, and extends the in-service life of gear pumps by optimizing lubrication and reducing the need for frequent overhauls, while maintaining performance across varying operating conditions.
Implementation Method 1
when the pressure of the fluid in the pump exceeds a threshold pressure, flow paths within the pump automatically open and allow fluid in the pump to flow to a shaft bearing interface
Implementation Method 2
the pressurized fluid that flows through the gear pump is used to lubricate internal components of the gear pump... the amount of lubrication desired at the bearing interface depends in part on the speed of rotation of the shaft and the pressure delivered by the pump, which are correlated to the amount of frictional forces that would be generated at the bearing shaft interface
Data Source
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AI summary
A gear pump that selectively directs lubrication to certain components within the pump. A system and method of retrofitting existing pumps to improve their longevity in the field. The system and method provides a clean, simple, efficient, and elegant improvement to current gear pump fuel delivery systems.