Pivotable Fan Blades Prevent Air Recirculation
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Solution Overview
Problem
In forced air electronics cooling systems, the failure of one fan can lead to a 'recirculation problem' where warm air is drawn back into the housing, causing heat buildup and potentially leading to component failure due to reduced air moving power and compromised operation of neighboring fans.
Innovation Solution
An improved fan design with pivotable fan blades that automatically transition from an open to a closed position when the spindle stops rotating, preventing air recirculation by blocking the passage and ensuring fresh air continues to be drawn into the housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional fixed fan design is used, then the structure is simple and manufacturing is easy, but when the fan fails, warm air recirculates back into the housing causing heat buildup and component failure
Solution Approach 1:
The fan blades are made pivotable about a radial axis, transitioning from a fixed structure to a dynamic one. When the fan operates, blades remain in a horizontal plane; when the fan fails, blades pivot downward to block air recirculation. This dynamic adaptation resolves the contradiction by enabling the simple structure to achieve reliable failure prevention.
Solution Approach 2:
The fan blade design enables automatic self-response to failure conditions. The pivotable blades naturally respond to fan failure by blocking recirculation without requiring external sensors, actuators, or control systems. This self-service mechanism improves reliability while avoiding additional complexity from external monitoring components.
2Productivity
If multiple fans are used in parallel, then cooling capacity increases, but the loss of one fan causes recirculation problems that compromise the operation of neighboring fans
Solution Approach 1:
Each fan in the parallel bank is segmented into independent functional units with pivotable blades. This segmentation allows each fan to independently manage its own failure condition without affecting neighboring fans. When one fan fails, its blades block recirculation locally, preventing the failure from propagating to other fans in the bank, thus maintaining overall system reliability and cooling capacity.
3Reliability
If fan blades are made pivotable with actuators, then automatic failure response is achieved, but additional components increase device complexity and cost
Solution Approach 1:
The fan blade design eliminates the need for external actuators and sensors by using the fan's own operational state to trigger the protective action. The pivotable blades respond automatically to fan failure through natural physical mechanisms, achieving reliable automatic failure response without adding complex control systems, actuators, or sensors.
Solution Approach 2:
The invention extracts the failure response function from external control systems and integrates it directly into the fan blade structure itself. By removing the need for separate actuators, sensors, and control electronics, the design achieves automatic failure response while reducing overall device complexity and component count.
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 solution effectively prevents heat buildup and reduces the risk of component failure by maintaining airflow and cooling efficiency even when a fan fails, without requiring additional external components, thus enhancing the reliability and efficiency of electronic components.
Implementation Method 1
each fan blade is pivotable about a radial axis between a closed position, where the each fan blade is in contact with each adjacent fan blade, and an axially displaced open position where the each fan blade is physically separated from the each adjacent fan blade
Implementation Method 2
automatically transition from an open to a closed position when the spindle stops rotating
Data Source
AI summary
A fan (200) includes a housing (201) defining a duct (202). A spindle (203) can be concentrically located about a central axis within the duct. One or more fan blades (205,206,207) extending radially from the spindle toward a surface of the duct. Each fan blade is pivotable about a radial axis (208) between a closed position (400) where the each fan blade is in contact with each adjacent fan blade and an axially displaced open position (300) where the each fan blade is physically separated from the each adjacent fan blade. This prevents recirculation of air if a fan should fail.