Fan and air conditioner
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Solution Overview
Problem
The existing fan designs experience stress concentration and imbalance due to excessive shearing stress at the adhesion interfaces between the vibration prevention member and metal, leading to potential cracks and increased vibration.
Innovation Solution
The fan incorporates a vibration prevention member with at least one of the outer or inner circumferential sections configured as a polygon, reducing shearing stress by converting the turning force into compression stress, thereby enhancing the reliability of the adhesion interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a circular adhesion interface is used between the vibration prevention member and metal, then the structure is simple and easy to manufacture, but excessive shearing stress and stress concentration occur leading to potential cracks and increased vibration
Solution Approach 1:
The patent applies asymmetry by changing the adhesion interface from a circular shape to a polygonal shape (such as hexagonal). This asymmetric geometric configuration redistributes the stress distribution pattern, converting concentrated shearing stress into compressive stress, thereby eliminating stress concentration points while maintaining manufacturing simplicity.
Solution Approach 2:
The patent changes the geometric parameter of the adhesion interface from circular to polygonal. This parameter change fundamentally alters the stress distribution characteristics, transforming the stress state from shearing-dominated to compression-dominated, which significantly improves the reliability of the adhesion interface without complicating the manufacturing process.
2Strength
If surface treatment is performed on the metal surfaces to secure shearing strength, then the adhesion strength is improved, but manufacturing cost increases
Solution Approach 1:
The patent changes the geometric parameter of the adhesion interface from circular to polygonal, which fundamentally alters the stress distribution. This parameter change transforms the stress state from shearing to compression, eliminating the need for surface treatment to enhance shearing strength, thereby reducing manufacturing cost while maintaining or improving adhesion strength.
Solution Approach 2:
The patent converts the potentially harmful shearing stress into beneficial compressive stress through the polygonal geometry design. This stress transformation not only eliminates the need for costly surface treatment but also enhances the overall reliability of the vibration prevention member by utilizing compression, which the rubber material can withstand more effectively.
3Stress or pressure
If concaves and convexes are formed on the adhesion interface to reduce shearing stress, then stress distribution is improved, but stress concentration occurs in corner portions leading to crack risk
Solution Approach 1:
The patent applies asymmetry by using a polygonal shape with flat sides and vertices instead of a circular shape. This asymmetric geometry distributes stress along the flat surfaces and concentrates it at the vertices in a controlled manner, converting shearing stress into compressive stress. This approach improves stress distribution without creating the harmful stress concentration found in concave-convex designs.
Solution Approach 2:
Instead of adding concaves and convexes to the surface (as in prior art), the patent inverts the approach by using a polygonal cross-section. This inversion transforms the stress mechanism from shearing (harmful) to compression (beneficial), eliminating crack risk while achieving stress distribution improvement.
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 shearing stress and stress concentration at the adhesion interfaces, improving the reliability and stability of the fan by distributing the turning force as compression stress, thus preventing imbalance and vibration.
Implementation Method 1
An electromagnetic exciting force generated by the motor 106 is absorbed and attenuated by the rubber material 125 to be prevented from being transmitted to the fan member 107
Implementation Method 2
At least one of an outer circumferential section of the inner cylinder and an inner circumferential section of the outer cylinder is configured as a polygon when viewed from the rotating shaft direction
Data Source
AI summary
A fan includes a fan member, a motor that drives to rotate the fan member, and a rotating shaft that is connected to the fan via a vibration prevention member and transmits a turning force of the motor to the fan. The vibration prevention member is an elastic member that connects an inner cylinder made of metal included in the rotating shaft and an outer cylinder made of metal included in the fan member. At least one of an outer circumferential section of the inner cylinder and an inner circumferential section of the outer cylinder is configured in a polygonal shape when viewed from the rotating shaft direction. A turning force received by the vibration prevention member acts as compression stress on an adhesion interface between a vibration prevention material and metal.