Axial Fan Hub With Elasto-Plastic Blades for Resonance Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Axial electric fans in automotive applications face challenges in minimizing axial dimensions while maintaining rigidity and reducing noise caused by resonance frequencies, as traditional damping methods like rubber dampers are impractical due to space constraints and material incompatibility with environmental conditions.
Innovation Solution
The axial fan design incorporates elasto-plastic blades with a specific shape and positioning to provide structural rigidity and damping effects, using sintered steel bushings for keying and minimizing the distance between hub components, while the elasto-plastic blades absorb energy to dampen resonance frequencies without adding materials or costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the distance between the bottom wall of the hub and the front wall of the electric motor is reduced to minimize axial dimensions, then the axial size of the axial electric fan is reduced, but the rigidity of the impeller assembly deteriorates and vibration increases
Solution Approach 1:
The hub is divided into distinct functional zones: a bottom wall for motor mounting, a intermediate region with reinforcement ribs, and a top wall for blade attachment. This segmentation allows each zone to be optimized independently - the bottom wall can be positioned close to the motor while the intermediate reinforcement provides structural rigidity, resolving the contradiction between compact axial dimension and structural strength
Solution Approach 2:
Instead of increasing axial distance to improve rigidity, the invention adds structural reinforcement in the radial and circumferential dimensions through reinforcement ribs and optimized hub geometry. This dimensional shift allows the hub to maintain rigidity without increasing axial length, enabling compact fan design while preserving structural integrity
2Object-generated harmful factors
If traditional rubber dampers are used to reduce vibration and noise, then damping effect is achieved, but the device complexity increases and material compatibility with environmental conditions deteriorates
Solution Approach 1:
The hub structure itself provides vibration damping through its elasto-plastic material properties and geometric design featuring reinforcement ribs. The hub's inherent structural characteristics enable it to absorb and dissipate vibration energy without requiring separate damper components, thus achieving vibration reduction while maintaining simple device architecture and avoiding material compatibility issues with rubber dampers
3Length of moving object
If the axial dimensions of the impeller are reduced to minimize fan size, then the axial size is reduced, but the structural limit for high output applications is compromised
Solution Approach 1:
The impeller is segmented into a compact hub section with optimized axial thickness and extended blade sections. The hub maintains minimum necessary axial dimension for structural integrity while the blades extend radially to provide the required surface area for air movement, enabling high power output within constrained axial space
Solution Approach 2:
The design compensates for reduced axial dimension by optimizing radial and circumferential dimensions - the blades are designed with extended radial length and optimized curvature to maintain effective air-moving surface area, allowing high power output to be achieved without increasing axial thickness
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 design effectively maintains rigidity and reduces noise by damping resonance frequencies, ensuring the fan operates within stringent environmental conditions without compromising structural integrity or increasing production costs.
Implementation Method 1
the elasto-plastic blades absorb energy to dampen resonance frequencies
Implementation Method 2
dampen resonance frequencies without adding materials or costs
Implementation Method 3
the bottom wall of the latter is equipped with a sintered steel bushing co-moulded with the bottom wall
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Described is an axial fan comprising an electric motor (3), an impeller (4) and a hub (5) of the impeller (4), the hub having a bottom wall (9) connected to the free end part of a shaft (14) of the electric motor in such a way as to rotate it about an axis (R) of rotation, the hub (5) being cup- shaped and having an outer annular wall (10) for containing at least partly the motor; the bottom wall (9) of the hub (5) has a central portion (11), an outer annular portion (12) connected to the central portion (11) by an intermediate portion (13) which is defined by a plurality of blades (16) arranged radially and angularly distributed about the axis of rotation, the blades (16) are elasto-plastic blades and are able to prevent the impeller (4) from moving axially parallel to the axis of rotation (R), moving radially perpendicular to the axis of rotation and a bending of the impeller (4) with movements normal to the plane in which the mean surface of the impeller itself lies, the blades (16) allowing on the other hand a movement with torsional bending around the axis of rotation so as to allow the damping of the resonance frequencies of the assembly formed by the impeller-shaft- rotor.