Blower Fan Impeller Mount Structure for Motor Vibration Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing blower fans fail to sufficiently reduce noise caused by electromagnetic vibration of the motor due to metallic contact between the impeller and the rotational shaft, despite the use of adhesive washers, as the frictional force from the nut can still transmit vibrations.
Innovation Solution
A blower fan design featuring a rotational shaft with a locking surface and rubber washers with specific arc and linear portions, along with a spacing portion in the impeller's mount hole, which prevents strong contact between the impeller and the rotational shaft, thereby reducing noise propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nut is tightened to fix the impeller to the rotational shaft, then the impeller is securely mounted, but frictional force causes the impeller to rotate with respect to the rotational shaft, resulting in strong metallic contact and noise transmission
Solution Approach 1:
The patent introduces rubber washers as an intermediary component between the impeller and the rotational shaft. These rubber washers are positioned between the impeller's mounting surface and the nut, serving as a mediator that absorbs electromagnetic vibrations while still allowing secure mounting. The rubber material provides friction to prevent rotation while dampening vibration transmission, thus resolving the contradiction between mounting reliability and noise reduction.
Solution Approach 2:
The patent changes the material parameter of the washer from metal to rubber, fundamentally altering the interaction between the impeller and rotational shaft. The rubber material has different friction characteristics and vibration absorption properties compared to metal, allowing the impeller to be securely mounted without strong metallic contact. This parameter change enables the system to maintain mounting reliability while significantly reducing noise transmission.
2Manufacturing precision
If the mount hole is sized to fittingly receive the rotational shaft, then the impeller is centered on the rotational shaft, but electromagnetic vibration propagates from the rotational shaft to the impeller, generating large noise
Solution Approach 1:
The rubber washers serve as an intermediary layer between the rotational shaft and the impeller's mount hole. This intermediary maintains the centering function by providing a stable interface while simultaneously absorbing electromagnetic vibrations before they can propagate to the impeller. The rubber material's damping properties break the direct vibration transmission path while preserving the geometric centering relationship.
Solution Approach 2:
The patent converts the harmful electromagnetic vibration into a beneficial effect by using the rubber washer's natural damping properties. The vibration energy that would otherwise be transmitted to the impeller is instead absorbed and dissipated by the rubber material through internal friction and hysteresis. This transforms the harmful vibration propagation into a beneficial vibration isolation effect.
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
The design effectively reduces noise by preventing metallic contact and absorbing electromagnetic vibrations, resulting in a quieter operation of the blower fan.
Implementation Method 1
the adhesiveness of the washers between the impeller and the metal washers absorbs any electromagnetic vibration of the motor, thus reducing noise generation
Implementation Method 2
rubber washers sandwiching a portion of the impeller having the mount hole
Data Source
AI summary
A rotational shaft is placed through insertion holes of rubber washers sandwiching a portion of an impeller having a mount hole. The impeller is mounted on the rotational shaft with a nut on a threaded distal end portion of the rotational shaft. The rotational shaft of the motor includes a locking surface. The insertion holes of the rubber washers each have the same shape as the cross-sectional shape of the rotational shaft. The mount hole of the impeller includes a spacing portion extending at an angle from the linear portion of the insertion hole of each rubber washer away from the locking surface of the rotational shaft. Although the impeller rotates with respect to the rotational shaft under a frictional force applied from the nut tightened against the rotational shaft, this structure prevents metallic contact between the impeller at the mount hole and the locking surface of the rotational shaft.