Wet Clutch Assembly With Isolated Lubrication and Control Pressure
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Solution Overview
Problem
Conventional clutch assemblies for aircraft low-speed spool turbomachines require improved lubrication and control pressure management to efficiently engage and disengage gear ratios, as existing systems lack efficient fluid isolation and lubrication distribution, leading to suboptimal performance and reliability.
Innovation Solution
A wet clutch assembly with axially located lubrication holes and a porting manifold that isolates control pressure and lubrication flow paths, allowing for precise fluid communication and distribution within the shaft channel, enabling the clutch to selectively engage and disengage based on hydraulic pressure, while maintaining lubrication for the clutch pack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional clutch assemblies are used without fluid isolation, then the structure is simpler, but lubrication and control pressure management become inefficient
Solution Approach 1:
The clutch assembly is segmented into distinct fluid zones using a separator plate that divides the fluid passage into a control pressure passage and a lubrication passage. This segmentation allows independent management of control pressure and lubrication functions, improving reliability without excessive complexity.
Solution Approach 2:
A porting manifold acts as an intermediary component that receives control pressure and lubrication fluid through separate hydraulic ports and distributes them to the clutch pack. The manifold mediates between the fluid sources and the clutch engagement mechanism, enabling efficient fluid management.
2Reliability
If lubrication holes are not axially located, then manufacturing is simpler, but lubrication distribution to the clutch pack is suboptimal
Solution Approach 1:
Lubrication holes are axially located within the bell flange at specific positions that correspond to the clutch pack geometry. This local positioning ensures that lubrication fluid is delivered precisely where needed in the clutch pack, maximizing lubrication effectiveness and reducing wear.
3Reliability
If control pressure and lubrication flow are not fluidly isolated, then the structure is simpler, but clutch operation predictability decreases
Solution Approach 1:
The fluid passage is segmented into separate control pressure and lubrication flow paths using a separator plate with distinct openings. This segmentation prevents fluid mixing and ensures predictable clutch operation by maintaining independent control over engagement pressure and lubrication flow.
Solution Approach 2:
A separator plate (thin film structure) is used to divide the fluid passage into isolated zones. The plate with selective openings creates fluid isolation while maintaining a relatively simple structure, enabling predictable operation without excessive complexity.
4Reliability
If no exit holes are provided in the outer bell flange, then the structure is simpler, but lubrication flow cannot exit the clutch pack
Solution Approach 1:
Exit holes are provided in the outer bell flange at specific locations to allow lubrication fluid to exit the clutch pack. This local feature ensures proper lubrication flow through the clutch pack and prevents fluid accumulation, improving lubrication efficiency.
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 solution enhances the clutch assembly's ability to transmit torque efficiently by isolating control pressure and lubrication flow, ensuring predictable operation across a wide speed band, reducing wear and heat buildup through effective lubrication, and improving the clutch's overall performance and reliability.
Implementation Method 1
a lubrication flow can travel to the clutch pack through the shaft and the bell flange
Implementation Method 2
The clutch pack can be selectively engaged or disengaged based on the hydraulic pressure
Data Source
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AI summary
A wet clutch assembly can include a clutch pack having a plurality of friction members attached to a first clutch housing and a plurality of separator members attached to a second clutch housing. The friction members and the separator members can be configured to be selectively contacted to each other to engage the first housing member to the second housing member. The clutch pack can be in fluid communication with a lubrication source such that a lubrication flow can flow to the friction members and the separator members to remove heat and/or debris therefrom.