Marine Drive Unit Cooling Oil Circuit Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing marine drive units face challenges in providing sufficient cooling capacity for the oil within the system, often relying on external water-cooling circuits which can be complex and inefficient.
Innovation Solution
A marine drive unit design featuring a dual oil pump system where a first oil pump handles lubrication and pressure for the upper bevel gear set, and a second oil pump operates a cooling oil circuit that recirculates and cools the oil within the unit, utilizing a bore in the drive shaft to facilitate oil flow and cooling, eliminating the need for a separate water-cooling circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single oil circuit is used for both lubrication and cooling, then device complexity is reduced, but cooling capacity becomes insufficient
Solution Approach 1:
The patent divides the oil management system into two separate circuits: a first oil circuit for lubrication and pressure supply, and a second oil circuit for cooling. This segmentation allows each circuit to be optimized independently, with the cooling circuit dedicated solely to thermal management, thereby resolving the contradiction between system simplicity and cooling effectiveness.
2Temperature
If separate water-cooling circuits are used, then cooling capacity is improved, but device complexity increases
Solution Approach 1:
The patent merges the cooling function with the existing lubricating oil system by using the same oil for both lubrication and cooling purposes. The oil serves dual functions: it provides lubrication through the first circuit and cooling through the second circuit that circulates oil through the bevel gear sets. This integration eliminates the need for separate water-cooling circuits while maintaining effective cooling capacity.
Solution Approach 2:
The lubricating oil is given multiple functions: it acts as both a lubricant for the bevel gear sets and as a cooling medium. The oil circulates through the gear sets, absorbs heat, and is then cooled by the second oil pump system, allowing a single substance to perform both protective and thermal management roles, thereby simplifying the overall system architecture.
3Productivity
If pump capacity and pressure are optimized separately for different circuits, then system performance is improved, but device complexity increases
Solution Approach 1:
The patent employs two separate oil pumps: a first oil pump for lubrication and pressure supply, and a second oil pump for cooling circulation. Each pump can be independently sized and optimized for its specific function, allowing the cooling pump to be optimized for flow rate while the lubrication pump is optimized for pressure, thereby achieving overall system performance optimization without excessive complexity.
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 design enhances cooling efficiency and simplifies the cooling process by using the same oil reservoir for both lubrication and cooling circuits, ensuring optimal capacity and pressure adjustment for each pump, thereby improving overall cooling capacity without requiring external water-cooling systems.
Implementation Method 1
a second oil pump is arranged to feed a cooling oil circuit... the second oil pump can be located at the lower end of the drive shaft to suck oil from an oil reservoir through a bore in the drive shaft and to pump it through a first opening at the second oil pump back into the oil reservoir
Implementation Method 2
The second oil pump can be located at the lower end of the drive shaft to suck oil from an oil reservoir through a bore in the drive shaft... The bore is preferably positioned coaxially to the centerline of the drive shaft... when the drive shaft is rotating
Data Source
AI summary
The present invention relates to a marine drive unit (1) comprising an upper bevel gear set (2) and a lower bevel gear set (3). The upper bevel gear set (2) is connected to the lower bevel gear set (3) by a drive shaft (4) which extends in vertical direction. A first oil pump (5) is arranged to supply oil to the upper bevel gear set (2) and a second oil pump (6) is arranged to feed a cooling oil circuit.