Boat Propulsion Cooling Pump Layout for Priming and Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric propulsion machines face challenges in reducing size and durability due to the use of rotary volume change pumps with rubber impellers, which require priming and are prone to damage when the motor rotation direction is reversed.
Innovation Solution
The electric propulsion machine employs a non-positive displacement pump, such as a centrifugal pump, located on the propeller shaft below the water surface to ensure easy priming and improved durability by reversing the impeller rotation direction without damaging the pump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a rotary volume change pump with rubber impeller is used to achieve high suction capacity, then the pump can suction out air and water effectively at start-up, but the pump size becomes large and durability decreases when rotation direction is reversed
Solution Approach 1:
The patent inverts the conventional pump configuration by placing the pump on the propeller shaft instead of the drive shaft. This allows the pump to rotate with the propeller shaft, which maintains consistent rotation direction regardless of motor reversal, thereby solving the durability issue while maintaining suction capacity through proper positioning below the water surface
2Device complexity
If the pump is disposed above the anti-cavitation plate, then the pump structure is simplified, but the periphery of the impeller is not filled with water at start-up requiring complex priming mechanisms
Solution Approach 1:
The patent positions the pump below the anti-cavitation plate where it is surrounded by water, creating an equipotential water environment around the impeller. This eliminates the need for priming by ensuring water is already present at the impeller periphery before operation, while the pump intake is positioned to face upward for easy water intake
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 allows for a compact design and enhanced durability by ensuring easy priming and maintaining pump functionality regardless of motor direction changes, thus reducing the overall size and weight of the propulsion machine.
Implementation Method 1
a non-positive displacement pump, such as a centrifugal pump, located on the propeller shaft below the water surface to ensure easy priming and improved durability by reversing the impeller rotation direction without damaging the pump
Implementation Method 2
a water jacket provided in the motor. These kinds of electric propulsion machines include a pump for supplying cooling water to a water jacket provided in the motor
Data Source
AI summary
An electric propulsion machine for propelling a boat. The electric propulsion machine includes a motor provided in an upper portion of the electric propulsion machine, a propeller shaft provided in a lower portion of the electric propulsion machine, a propeller provided in the propeller shaft, a drive shaft extending in an upper-lower direction and configured to transmit rotation of the motor to the propeller shaft, and a first non-positive displacement pump provided in the propeller shaft and configured to supply cooling water to the motor, the cooling water cooling the motor.