Tilt Pad Journal Bearing Nozzle Layout for Lower Metal Temperature
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Solution Overview
Problem
Tilt pad journal bearings in turbomachines face challenges with hot oil flow from upstream pads to downstream pads, leading to increased power loss and bearing metal temperature, which reduces their performance.
Innovation Solution
A tilt pad journal bearing design featuring an annular support ring with arcuate pads and a lubrication arrangement that includes a lubrication manifold and nozzles, where the central nozzle has a larger cross-sectional flow area than others, directing lubricant efficiently to the oil mixing cavity to reduce bearing metal temperature and power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hot oil from upstream pad flows to downstream pad, then lubrication is maintained, but power loss increases and bearing metal temperature increases
Solution Approach 1:
The patent extracts and removes the harmful hot oil from the bearing system by introducing a separate cooling lubricant supply that delivers fresh, cool lubricant directly to the bearing contact surfaces, preventing the circulation of heated oil that causes energy loss
Solution Approach 2:
The patent introduces an intermediary cooling lubricant supply system that acts as a mediator between the lubrication needs and thermal management requirements, delivering cool lubricant through a dedicated manifold and nozzle system separate from the main lubrication circuit
2Reliability
If hot oil from upstream pad flows to downstream pad, then lubrication is maintained, but bearing metal temperature increases
Solution Approach 1:
The patent extracts and removes the harmful hot oil from the bearing system by introducing a separate cooling lubricant supply that delivers fresh, cool lubricant directly to the bearing contact surfaces, preventing the circulation of heated oil that causes temperature rise
Solution Approach 2:
The patent changes the thermal parameter of the lubricant by supplying it at a lower temperature through the cooling lubricant supply, thereby reducing the bearing metal temperature while maintaining adequate lubrication
3Quantity of substance
If central lubrication nozzle has larger cross-sectional flow area, then lubricant flow to oil mixing cavity increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies local quality by providing different nozzle configurations at different locations - the central lubrication nozzle has a larger cross-sectional flow area compared to other nozzles, optimizing lubricant distribution to the oil mixing cavity while maintaining manufacturability through localized differentiation rather than uniform design
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 design enhances lubrication efficiency, reduces bearing metal temperature, and minimizes power loss by effectively managing lubricant flow and mixing, thereby improving the overall performance of the tilt pad journal bearing.
Implementation Method 1
A cross-sectional flow area of at least one of the plurality of lubrication nozzles positioned toward a center of the lubrication manifold may be larger than a cross-sectional flow area of a remainder of the plurality of nozzles positioned away from the center of the lubrication manifold
Data Source
Figure 1
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AI summary
A tilt pad journal bearing (200) for supporting a rotating shaft includes an annular support ring (202) and a plurality of arcuate pads (204) tiltably mounted in the annular support ring (202) and circumferentially spaced apart from each other. The tilt pad journal bearing further has a lubrication arrangement (232) disposed between each pair of the plurality of arcuate pads (204). The lubrication arrangement (232) includes a lubrication manifold (234) connected to the annular support ring (202) and recessed relative to a shaft support surface (218) of adjacent arcuate pads to define an oil mixing cavity (248), and a plurality of lubrication nozzles (236) protruding from the lubrication manifold (234) into the oil mixing cavity (248). A cross-sectional flow area of at least one of the plurality of lubrication nozzles (236) positioned toward a center of the lubrication manifold is larger than a cross-sectional flow area of a remainder of the plurality of nozzles (236).