Tidal Runner Blade Reversal via Annular Piston Servomotor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing mechanisms for reversing blades in tidal power plant runner units face inefficiencies due to limited angle rotation and mechanical complexity, leading to reduced efficiency in reverse mode operations and increased wear from multiple moving parts.
Innovation Solution
A device comprising an annular lever, main and reversing servomotors with pistons, and a connecting rod with an eccentrically fixed end, allowing for complete blade inversion beyond 180 degrees with reduced mechanical stress and wear by using oil-operated systems and synchronized piston movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fixed blade direction is used in the runner unit, then the efficiency is acceptable in direct mode operation, but the efficiency significantly decreases in reverse mode operation
Solution Approach 1:
The blade is made dynamically adjustable through a control mechanism that enables rotation about the shaft axis. The blade can be positioned at different angles depending on the operating mode (direct or reverse), transforming from a static fixed-orientation component to a dynamic adjustable component. This allows the blade profile to be optimally aligned with water flow in both directions, resolving the efficiency loss in reverse mode while maintaining adaptability.
2Device complexity
If a control mechanism with limited rotation angle (less than 40 degrees) is used, then the mechanism is simpler, but complete blade inversion (more than 180 degrees) cannot be achieved
Solution Approach 1:
The control mechanism is segmented into two independent systems: a primary control mechanism for normal operation within limited rotation angles, and a reversing mechanism specifically designed to enable complete blade inversion beyond 180 degrees. This segmentation allows each subsystem to be optimized for its specific function, with the reversing mechanism handling the complex large-angle rotation while the primary mechanism maintains simplicity for routine adjustments.
Solution Approach 2:
A reversing mechanism acts as an intermediary between the simple primary control mechanism and the blade, enabling complete inversion. The reversing mechanism includes components such as a reversing motor, pinion gear, and rack that work together to provide the additional rotation capability without requiring the entire control system to be complex.
3Adaptability or versatility
If an auxiliary mechanism with rotative gear and multiple moving parts is added to enable complete blade inversion, then the blade can rotate more than 180 degrees, but the mechanism becomes heavier and experiences increased wear
Solution Approach 1:
The reversing function is extracted as a separate, dedicated mechanism rather than being integrated into the primary control system. This allows the reversing mechanism to be independently optimized and only engaged when needed for complete blade inversion. The extraction enables using lighter, more wear-resistant materials specifically for the reversing components, and reduces the overall system weight compared to making the entire control mechanism heavy-duty.
Solution Approach 2:
The reversing mechanism replaces traditional heavy mechanical linkages with a more efficient gear-rack system driven by a reversing motor. This substitution reduces the number of moving parts, minimizes friction and wear interfaces, and decreases the overall weight of the reversing subsystem while maintaining the capability for complete blade inversion.
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
Enhances efficiency in both direct and reverse modes by enabling full blade inversion with reduced mechanical stress and wear, improving overall energy generation capabilities in tidal power plants.
Implementation Method 1
a main servomotor (5) comprising a first piston (51) adapted to reciprocate along a shaft (31) of the runner unit (30)
Implementation Method 2
The servomotors (5, 60) may be of an oil type
Data Source
AI summary
Embodiments of the present invention generally relate to a runner unit of a tidal power plant, and more particularly to a device for reversing a blade of the runner unit. The device according to the embodiments is lighter and more efficient with respect to known solutions which involve articulated mechanisms as it is based on a reversing servomotor including an annular piston which acts on the blade to be reversed.