Submerged Lubricant Pump for Windmilling Turbine Bearings
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Solution Overview
Problem
Conventional lubrication systems for turbine engines are unable to effectively lubricate bearings during windmilling conditions, where rotational velocities are low or near zero, due to the mechanical lubricant pump's reliance on high rotational velocity to generate suction and draw lubricant from the reservoir.
Innovation Solution
A lubrication system with a lubricant reservoir that submerges the lubricant pump, allowing it to remain primed and lubricate bearings at low rotational velocities, utilizing a clutch to mechanically couple or decouple the pump from the rotating assembly based on velocity, and including a lubricant flow regulator to ensure efficient lubrication during windmilling and other modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical lubricant pump is used to draw lubricant from the reservoir, then lubrication can be provided during normal operation, but the pump cannot generate sufficient suction at low or near zero rotational velocities to lubricate bearings during windmilling
Solution Approach 1:
The pump is pre-filled with lubricant and kept primed by submerging it in the lubricant reservoir. This preliminary preparation ensures that the pump has lubricant ready to deliver immediately when activated, without needing to draw lubricant through suction at low speeds.
Solution Approach 2:
The pump is positioned at the same gravitational level as the lubricant reservoir, eliminating the need for the pump to lift lubricant against gravity. This equipotential arrangement removes a barrier to lubricant flow, allowing the pump to operate effectively at low rotational velocities.
2Ease of operation
If the lubricant pump is positioned above the lubricant reservoir to facilitate lubricant flow, then gravity can assist lubricant delivery, but the pump cannot remain primed and will lose lubricant priming at low speeds
Solution Approach 1:
The pump is positioned at the same gravitational level as the lubricant reservoir, eliminating the need for the pump to lift lubricant against gravity. This equipotential arrangement removes a barrier to lubricant flow, allowing the pump to operate effectively at low rotational velocities.
Solution Approach 2:
A lubricant delivery mechanism (such as a valve or controlled flow path) acts as an intermediary between the reservoir and pump, ensuring lubricant flows to the pump while maintaining the pump's primed state through proper sealing and flow control.
3Productivity
If the lubrication system is designed to operate at high rotational velocities, then the pump can generate sufficient suction, but the system cannot provide lubrication during windmilling or near zero velocity operations
Solution Approach 1:
The pump is pre-filled with lubricant and kept primed by submerging it in the lubricant reservoir. This preliminary preparation ensures that the pump has lubricant ready to deliver immediately when activated, without needing to draw lubricant through suction at low speeds.
Solution Approach 2:
The clutch provides dynamic coupling and decoupling of the pump from the rotating assembly based on operational conditions. This dynamic control allows the system to adapt to varying rotational velocities, engaging the pump only when needed for supplemental lubrication.
4Reliability
If a clutch is added to mechanically couple or decouple the pump based on velocity, then the pump can be activated only when needed, but the device complexity increases
Solution Approach 1:
The clutch is designed to automatically engage and disengage based on the rotational velocity of the rotating assembly, without requiring external control systems. This self-regulating mechanism simplifies the overall control architecture while ensuring proper timing of pump activation.
Solution Approach 2:
The clutch responds to changes in rotational velocity parameter, engaging the pump when velocity drops below a threshold and disengaging when velocity exceeds the threshold. This parameter-based control provides simple, reliable automation without complex control systems.
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
Enables effective lubrication of bearings at low or zero rotational velocities, preventing wear and maintaining pump priming without the need for high suction, facilitating line replaceable unit configurations for ease of maintenance.
Implementation Method 1
positioned at a same gravitational level as the lubricant reservoir so as to facilitate flow of lubricant to the lubricant pump
Implementation Method 2
configured to lubricate the bearing as the fan rotor rotates at less than about five revolutions per minute (∼5rpm)
Data Source
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AI summary
A system is provided for a turbine engine. This turbine engine system includes a rotating assembly 39, a bearing 54 and a lubrication system 56. The bearing 54 is configured with the rotating assembly 39. The lubrication system 56 is configured to lubricate the bearing 54. The lubrication system 56 includes a lubricant pump 60 and a lubricant reservoir 58. The lubricant pump 60 is mechanically coupled with and driven by the rotating assembly 39. The lubricant pump 60 is configured with the lubricant reservoir 58 so as to be at least partially submersed in lubricant contained within the lubricant reservoir 58.