Transfer Case Lubrication System Windage Oil Transfer
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Solution Overview
Problem
Conventional transfer case lubrication systems face challenges in minimizing parasitic losses and reducing manufacturing complexity while maintaining superior operational characteristics such as efficiency and ground clearance.
Innovation Solution
The lubrication system features a housing with a partition defining a reservoir chamber, a pair of sprockets connected by an endless chain to generate a windage force for oil transfer, and a pump assembly with an oil pump and spray bar to direct oil from the reservoir chamber to the inner chamber, minimizing aeration and parasitic losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional pump assembly designs are used with pickup disposed in the reservoir, then oil can be pumped to various components, but parasitic losses and aeration increase due to oil splashing and churning
Solution Approach 1:
The pickup is extracted from the reservoir and repositioned to be in fluid communication with the inner chamber where oil is sprayed onto components. This eliminates the need for the pickup to churn through oil in the reservoir, significantly reducing parasitic losses and aeration while maintaining the ability to pump oil to all necessary components.
Solution Approach 2:
A spray bar is introduced as an intermediary device that distributes oil from the inner chamber to various components. This mediator allows oil to be delivered efficiently without requiring the pickup to be submerged in oil, thereby reducing energy losses from oil splashing and churning.
2Reliability
If pickup is disposed in the reservoir chamber, then oil can be drawn from reservoir, but oil aeration and parasitic losses increase from oil splashing
Solution Approach 1:
The pickup is taken out of the reservoir chamber and repositioned to draw oil from the inner chamber via the spray bar system. This extraction eliminates the harmful interaction between the pickup and oil in the reservoir, reducing aeration and energy consumption while maintaining reliable lubrication delivery to all components.
3Loss of energy
If complex pump assembly designs are used to minimize parasitic losses, then energy efficiency improves, but manufacturing cost and complexity increase
Solution Approach 1:
The spray bar serves multiple functions: it distributes oil to various components for lubrication, acts as a conduit for oil flow, and enables the pickup to be positioned optimally without being submerged in oil. This multi-functionality achieves energy efficiency while maintaining manufacturing simplicity by eliminating the need for complex additional components.
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
This configuration significantly reduces parasitic losses, enhances operational efficiency, and simplifies manufacturing while improving packaging and component life, resulting in a more efficient and cost-effective transfer case design.
Implementation Method 1
The chain is spaced from the partition so as to generate a windage force for transferring oil from the inner chamber to the reservoir chamber in operation
Implementation Method 2
a spray bar in fluid communication with the oil pump for directing oil pumped from the reservoir chamber to a predetermined location within the inner chamber
Data Source
AI summary
The present invention relates to a transfer case (16) lubrication system (42) that includes a housing (44) defining a chamber and having a lower portion (58). A partition (46) extends from the lower portion (58) and is disposed in the chamber so as to define a reservoir for oil, adjacent to the partition (46) and spaced from the chamber. First and second sprocket (50)s are supported in the chamber, with the first sprocket (48) being spaced from the reservoir. The system also includes a pump assembly (52) having an oil pump (78), a pickup (80) in fluid communication with the pump and at least partially disposed in the reservoir, and a spray bar (82) in fluid communication with the pump for directing oil from the reservoir to a predetermined location within the chamber. A chain (54) connects the sprockets and is spaced from the partition (46) so as to generate a windage force for transferring oil from the chamber to the reservoir in operation.