Transfer Case Lubrication Valve Control
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Solution Overview
Problem
Current transfer case lubrication systems lack control over lubricant delivery, leading to inefficient lubrication during different vehicle operation modes, resulting in parasitic losses and spin losses when the clutch is disengaged in two-wheel drive mode.
Innovation Solution
A lubrication system with a pump and valve configuration that allows for controlled lubricant flow based on vehicle operation mode, using a valve with a control mechanism to restrict or allow lubricant flow, reducing unnecessary lubrication and associated losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pump is mounted on the input shaft or primary output shaft to deliver lubricant through axial bores, then lubrication is provided to transfer case components, but control over lubricant delivery is limited and parasitic losses occur during two-wheel drive mode
Solution Approach 1:
The valve is configured to switch between a first position that allows free flow of lubricant and a second position that restricts lubricant flow. This dynamic positioning of the valve based on operating mode enables the system to adapt lubrication delivery, reducing parasitic losses during two-wheel drive mode while maintaining reliable lubrication when needed.
2Reliability
If lubricant flows continuously through the axial bore to all components, then all components receive lubrication, but unnecessary lubrication occurs when the clutch is disengaged, causing spin losses
Solution Approach 1:
The valve structure includes a first valve outlet and a second valve outlet that can be selectively opened or closed. This segmentation of the flow path allows the system to direct lubricant only to specific components based on operating mode, preventing unnecessary lubrication of the clutch when disengaged and reducing spin losses while maintaining component lubrication when needed.
3Loss of energy
If the valve restricts lubricant flow during two-wheel drive mode, then parasitic losses are reduced, but lubrication control complexity increases
Solution Approach 1:
The valve is positioned to be directly actuated by the clutch assembly, allowing the clutch's own position (engaged or disengaged) to control the valve state. This self-service arrangement eliminates the need for external sensors or complex control systems, reducing device complexity while enabling parasitic loss reduction during two-wheel drive mode.
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 and spin losses by optimizing lubricant delivery, improving fuel efficiency and power availability during two-wheel drive mode by limiting lubricant flow when not needed, thereby enhancing drivetrain performance.
Implementation Method 1
a pump that is operable to supply a lubricant along a fluid flow path extending from a lubricant source to one or more components
Implementation Method 2
a second valve outlet that is operable to restrict flow of the lubricant along the fluid flow path in a second state
Data Source
AI summary
A lubrication system (300, 400) for a transfer case (200) includes a pump (240) in fluid communication with a lubricant source (243) and a power transfer assembly as well as a valve (302, 402) positioned along a fluid flow path between the lubricant source (243) and the power transfer assembly. The valve (302, 402) includes a valve inlet (306), a first valve inlet (406), a first valve outlet (308, 408) that does not restrict flow of the lubricant along the fluid flow path in a first state, a second valve outlet (310, 410) that is operable to restrict flow of the lubricant along the fluid flow path in a second state, and a control that is operable to open the first valve outlet (308, 408) in the first state and open the second valve outlet (310, 414) in the second state.