Marine Propeller Shaft Sealing With Dual Lubrication Cooling
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Solution Overview
Problem
The temperature rise of lubricant in the shaft seal arrangement leads to increased lubricant consumption and wear of the shaft seal arrangement in marine vessel propeller shafts.
Innovation Solution
A dual lubrication system with separate lubricant circulation lines and circulators, combined with a heat exchanger to transfer thermal energy between the lines, maintains distinct lubricant compositions and reduces temperature, thereby minimizing lubricant consumption and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single lubrication system is used for both bearing arrangement and shaft seal arrangement, then device complexity is reduced, but lubricant temperature rises causing increased wear and lubricant consumption
Solution Approach 1:
The lubrication system is divided into two independent circuits: a first lubrication arrangement for the bearing arrangement and a second lubrication arrangement for the shaft seal arrangement. This segmentation allows each circuit to be optimized independently, preventing temperature rise in the shaft seal circuit while maintaining system reliability.
Solution Approach 2:
A heat exchanger is introduced as an intermediary component between the two lubrication circuits. The heat exchanger transfers thermal energy from the lubricant in the second circuit to the lubricant in the first circuit, cooling the shaft seal lubricant without direct mixing of the two lubricants, thus reducing wear and consumption.
2Device complexity
If lubricant temperature in shaft seal arrangement is not controlled, then device complexity remains low, but lubricant consumption increases due to temperature rise
Solution Approach 1:
The heat exchanger serves as a thermal intermediary that transfers heat from the lubricant in the shaft seal arrangement to the lubricant in the bearing arrangement. This indirect heat transfer mechanism reduces lubricant temperature and consumption without requiring complex cooling systems or direct lubricant replacement.
Solution Approach 2:
The lubricant in the first bearing arrangement acts as a cooling medium for the lubricant in the second shaft seal arrangement through the heat exchanger. The system utilizes its own operational components (the bearing lubricant circulation) to provide thermal management for the shaft seal lubricant, reducing external cooling requirements.
3Device complexity
If lubricant temperature in shaft seal arrangement is not controlled, then device complexity remains low, but wear of shaft seal arrangement increases
Solution Approach 1:
By separating the lubrication systems and implementing dedicated thermal management for the shaft seal arrangement through the heat exchanger, the patent extends the service life of the shaft seal components. The segmented approach allows precise temperature control in the critical shaft seal circuit without affecting the bearing circuit.
Solution Approach 2:
The heat exchanger acts as a thermal mediator that selectively cools the lubricant in the shaft seal arrangement, reducing thermal stress and wear on the shaft seal components. This extends the duration of action and service life of the stationary shaft seal arrangement without requiring complete system redesign.
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 effectively lowers lubricant temperature, reducing consumption and wear of the shaft seal arrangement, ensuring efficient and prolonged operation of the propeller shaft sealing mechanism.
Implementation Method 1
a first heat exchanger (11) in thermal contact with the first lubricant circulation line (5) and in thermal contact with the second lubricant circulation line (9) for transferring thermal energy between first lubricant flowing in the first lubricant circulation line (5) and second lubricant flowing in the second lubricant circulation line (9)
Data Source
Figure 1~2
Figure 3~4
AI summary
Presented is an arrangement and a method for sealing a propeller shaft (1) of a marine vessel. The arrangement comprises a propeller shaft (1) rotatable supported with at least one bearing (2), a bearing arrangement (3), a first lubrication arrangement (4) comprising a first lubricant circulation line (5) for conducting first lubricant to and from said bearing arrangement (3), a shaft seal arrangement (7) for sealing the propeller shaft (1) against sea water, and a second lubrication arrangement (8) comprising a second lubricant circulation line (9) for conducting second lubricant to and from said shaft seal arrangement (7). A first heat exchanger (11) is in thermal contact with the first lubricant circulation line (5) and in thermal contact with the second lubricant circulation line (9).