Dry Sump Engine Assembly With External Reservoir for Long Oil Life
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Solution Overview
Problem
Existing small internal combustion engines for outdoor power equipment, such as lawn mowers, require frequent oil changes due to limited engine oil life, leading to increased maintenance and operational downtime, especially during peak usage seasons.
Innovation Solution
A dry sump lubrication system with an external oil reservoir and dual pumps (supply and return) that extends engine oil life by providing a larger oil capacity, allowing for at least 500 hours of operation without oil change, reducing maintenance and labor costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a conventional lubrication system with integrated oil pan is used, then the engine structure is simple, but the engine oil life is limited requiring frequent oil changes
Solution Approach 1:
The lubrication system is segmented into separate functional components: an external oil reservoir tank separated from the engine block, a supply pump independently mounted, and a return pump separately positioned. This segmentation allows each component to be optimized independently and enables the oil capacity to be significantly increased without proportionally increasing engine block complexity.
Solution Approach 2:
The oil reservoir is positioned externally in a different spatial dimension away from the engine block, connected via hoses and pumps. This dimensional relocation allows the oil storage capacity to be expanded without increasing the footprint or complexity of the engine assembly itself, enabling extended oil life while maintaining compact engine dimensions.
2Loss of time
If an external oil reservoir with larger capacity is used, then the engine oil life is extended, but the system complexity increases with dual pumps and external tank
Solution Approach 1:
The return pump automatically draws oil from the crankcase and returns it to the external reservoir without requiring manual intervention. The supply pump automatically delivers pressurized oil from the reservoir to the engine galleries. This self-service operation eliminates the need for manual oil level monitoring and top-up, reducing maintenance downtime despite the increased system complexity.
Solution Approach 2:
The dual pump system maintains continuous oil circulation and pressure throughout extended operation periods. The supply pump continuously delivers fresh oil from the large-capacity reservoir, while the return pump continuously removes used oil, ensuring uninterrupted lubrication and enabling the engine to operate for extended periods (500+ hours) without maintenance intervention.
3Reliability
If frequent oil changes are performed, then the engine wear is reduced, but the operational downtime and labor costs increase
Solution Approach 1:
The system changes the key parameter of oil capacity from the conventional small integrated pan to a large external reservoir, increasing oil volume by a factor of 5 or more. This parameter change extends the time between oil degradation and replacement, maintaining reliable engine performance over extended periods (500+ hours) without requiring frequent oil changes, thus preserving both engine reliability and operational productivity.
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 significantly extends engine oil life, reducing oil change frequency and maintenance needs, enabling continuous operation during peak seasons without oil changes, and lowering operational costs by maintaining engine performance and reducing wear.
Implementation Method 1
The supply pump is in fluid communication with the oil chamber and the oil gallery and the supply pump is configured to draw oil from the oil chamber and provide pressurized oil to the oil gallery
Implementation Method 2
The return pump in fluid communication with the crankcase chamber and the filter chamber and the return pump is configured to draw oil from the crankcase chamber and provide pressurized oil to the filter chamber
Implementation Method 3
The filter is configured to filter the pressurized oil provided to the filter chamber
Data Source
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AI summary
An engine assembly includes a small air-cooled engine and a dry sump lubrication system including an external oil reservoir, wherein the dry sump lubrication system has an overall oil capacity that provides at least five hundred hours of engine oil life.