Marine Pump Phase Shift for Noise Reduction
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Solution Overview
Problem
Existing pump apparatuses for marine vessels face challenges in efficiently adjusting tilt and trim angles due to noise generation from synchronized pulsation in multiple pumps, which affects the propulsive efficiency and operational stability.
Innovation Solution
The design incorporates a shaft with a first and second pump, each having a pair of gears with different engagement timings to minimize noise by shifting their operational phases, ensuring that the first and second operating fluids are fed at distinct timings, thereby reducing synchronized noise and enhancing operational stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple pumps are used to supply operating fluid to the cylinder apparatus, then the productivity and fluid supply capability are improved, but noise is generated due to synchronized pulsation from all pumps operating at the same phase
Solution Approach 1:
The patent applies periodic action by setting different rotational phases for multiple pumps (first pump at 0°, second pump at 180°) so that their pulsation cycles are staggered. This causes the suction and discharge phases of each pump to occur at different times, eliminating synchronized pulsation and reducing noise while maintaining the combined fluid supply capability of all pumps.
2Productivity
If multiple pumps operate in synchronization, then the fluid supply efficiency is improved, but vibrations are increased due to synchronized pulsation
Solution Approach 1:
The patent implements periodic action with phase shifting, where the first pump operates at a reference phase and the second pump operates at a phase shifted by 180 degrees. This staggered periodic operation ensures that when one pump is at peak discharge, the other is at peak suction, thereby canceling out vibrations and improving operational stability while maintaining efficient fluid supply.
3Device complexity
If all pumps feed operating fluid at the same timing, then the system complexity is reduced, but noise and vibrations are increased due to synchronized operation
Solution Approach 1:
The patent applies asymmetry by introducing phase differences between identical pumps. Although the pumps themselves are symmetric in design and function, their operational phases are made asymmetric (0° and 180°), which breaks the synchronization that causes noise and vibrations. This simple phase offset requires minimal additional control complexity while effectively reducing harmful factors.
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 effectively reduces noise and improves the operational stability of the marine vessel propelling system by ensuring that the fluid flow into the cylinder apparatus is synchronized, leading to enhanced propulsive efficiency and reduced vibrations.
Implementation Method 1
The first pump includes a first driving gear disposed on the shaft in a first phase and rotatable with the shaft to feed a first operating fluid. The second pump includes a second driving gear disposed on the shaft in a second phase shifted from the first phase.
Data Source
AI summary
A pump apparatus includes a shaft, a first pump, and a second pump. The first pump includes a first driving gear disposed on the shaft in a first phase and rotatable with the shaft to feed a first operating fluid. The second pump includes a second driving gear disposed on the shaft in a second phase shifted from the first phase. The second driving gear is coaxial with the first driving gear and rotatable with the shaft to feed a second operating fluid.