Blower Air Inlet Annular Ribs Noise Reduction
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Solution Overview
Problem
Conventional blowers generate noise due to fluid entering rapidly through the air inlet opening, causing a portion of the fluid to pass through gaps between the casing and fan, leading to annoying noise issues.
Innovation Solution
The blower design incorporates a first and second annular rib protruding from the air inlet opening and inner bottom surface of the upper housing, with arc-shaped cross-sectional profiles, to guide fluid flow smoothly and reduce noise by creating an air curtain that prevents escaped airflow from continuing to generate noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the air inlet opening is formed through the upper housing with flat surfaces, then the manufacturing is simple, but fluid passes through the gap between the upper housing and fan causing noise
Solution Approach 1:
The patent applies curvature by forming arc-shaped first and second annular ribs at the air inlet opening. These curved ribs guide the fluid flow smoothly along the fan surface, preventing turbulence and noise generation while maintaining manufacturing feasibility through standard molding techniques.
Solution Approach 2:
The patent introduces annular ribs as intermediary structures between the air inlet opening and the fan. These ribs act as flow guides that mediate the interaction between incoming fluid and the fan, directing flow through the intended path and preventing direct gap passage that causes noise.
2Object-generated harmful factors
If the first and second annular ribs are added to guide fluid flow, then noise is reduced, but the device complexity increases
Solution Approach 1:
The patent applies local quality by adding annular ribs only at the critical air inlet opening region where noise generation occurs. The ribs are localized features rather than comprehensive structural changes, modifying flow characteristics only where needed while leaving the rest of the housing simple.
Solution Approach 2:
The arc-shaped cross-section of the annular ribs provides smooth flow guidance with minimal structural complexity. The curved geometry naturally directs flow without requiring complex mechanical components, achieving noise reduction through simple geometric modification.
Data Source
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AI summary
[CHINESE] A blower includes an upper housing and a lower housing. An air flow space and an air outlet passage are formed inside and communicate with each other. A fan is mounted in the upper housing and the lower housing. A motor is mounted outside the lower housing. A driving shaft of the motor passes through the lower housing and is connected to the fan. The upper housing has an air inlet opening that corresponds to the air inlet hole on the top of the fan. The upper housing has a first annular rib with an arc-shaped surface at an edge of the air inlet opening. The upper housing has a second annular rib protruding on an inner bottom surface of the upper housing and adjacent to the air inlet opening. When an external fluid flows in the air inlet opening, the fluid can smoothly pass through the arc-shaped surface of the first annular rib. The fluid is then transported by the fan to the air flow space. A part of the fluid is blocked by the second annular rib, and thus forms a vertical downward airflow curtain, which significantly reduces noise generation and enhances the noise reduction effect. [DESCRIPTION OF THE REFERENCE NUMBERS IN THE REPRESENTATIVE DRAWING] 10: upper housing 100: air flow space 11: air inlet opening 111: first annular rib 112: second annular rib 113: annular recess 12: upper annular flow passage 13: upper air outlet passage 20: lower housing 21: base 22: lower annular flow passage 23: lower air outlet passage 30: fan 31: blade 32: upper plate 320: air inlet hole 34: lower plate 40: motor 41: driving shaft