Fan Ring Part Design to Reduce Backflow Air Through Clearance
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Solution Overview
Problem
Conventional fans experience reduced efficiency due to backflow air flowing back into the intake side, which decreases the airflow volume blown out by the fan, and existing solutions focus more on noise reduction rather than addressing backflow volume.
Innovation Solution
The fan design includes a ring part with a third extending part that covers at least half the clearance between the ring part and the flow rectifying member, detouring backflow air and increasing resistance, thereby reducing backflow volume and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a clearance is formed between the ring part and the flow rectifying member to allow rotation, then the ring part can rotate with the vanes, but backflow air flows reversely through the clearance toward the intake side, reducing fan efficiency
Solution Approach 1:
A third part is introduced as an intermediary structure extending from the ring part toward the flow rectifying member. This third part acts as a mediator that blocks the reverse flow path of backflow air through the clearance, while allowing the ring part to still rotate with the vanes. The third part effectively separates the rotation function from the backflow prevention function.
2Productivity
If the third part extends on the radially outer side than the flow rectifying member end, then backflow air is detoured and backflow volume reduces, but the structure becomes more complex
Solution Approach 1:
The ring part is segmented into multiple functional parts: a first part, a second part, and a third part. Each part serves a specific function - the first and second parts maintain the rotational connection, while the third part specifically addresses backflow prevention. This segmentation allows the complex backflow control function to be added without redesigning the entire ring part structure.
3Productivity
If the first dimension of the third part is at least 0.5 times the first distance, then sufficient resistance is provided to detour backflow air, but the radial size of the fan increases
Solution Approach 1:
The design specifies that the first dimension of the third part should be at least 0.5 times the first distance (the straight-line distance between the flow rectifying member end and the virtual point). This parameter relationship provides sufficient resistance to detour backflow air while controlling the radial dimension increase. The 0.5 ratio is optimized to balance efficiency improvement with size constraints.
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 significantly reduces backflow volume, enhancing the fan's efficiency and preventing a size increase, leading to improved airflow and performance.
Implementation Method 1
the third part provides resistance on the backflow air (the air that reversely flows through the clearance between the ring part and the flow rectifying member) flowing toward a point where it merges with the intake air
Data Source
AI summary
A fan includes a core part, a vanes, a ring part and a flow rectifying member. The ring part includes first second and third parts. The first part includes a first end overlapping with a flow rectifying member end and extends axially on a radially inner side of the flow rectifying member. The second part includes a second end spaced from the flow rectifying member end, overlapping with the flow rectifying member, and connected to the first end. The third part is connected to the second end, and extends on the radially outer side of the flow rectifying member end. The second end overlaps with a virtual point reached by the flow rectifying member end being linearly extended toward an upstream side. A first dimension, a radial length of the third part, is at least 0.5 times a first straight-line distance between the flow rectifying member end and the virtual point.