Electric Blower Fan Case Openings for Cooling and Air Discharge
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Solution Overview
Problem
Conventional electric blowers in vacuum cleaners face inefficiencies in suction power due to limitations in air discharge through openings on the fan case, which restrict the enhancement of blower efficiency.
Innovation Solution
The electric blower design includes protrusions with brims covering part of the openings on the fan case, allowing for larger discharge areas and efficient airflow, with the brim covering 30-75% of the opening area to balance cooling and discharge, thereby improving efficiency and reducing heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If openings are made larger on the fan case to discharge more air, then blower efficiency improves, but motor cooling effectiveness deteriorates
Solution Approach 1:
The fan case is divided into multiple openings distributed around its circumference, with each opening partially covered by protrusions. This segmentation allows different regions to serve different functions: some areas discharge air for efficiency while other areas allow air to pass through for motor cooling, resolving the contradiction between blower efficiency and cooling effectiveness.
Solution Approach 2:
Different regions of the fan case are given different properties through the strategic placement and sizing of protrusions at specific openings. Some openings have larger coverage areas to prioritize cooling, while others have smaller coverage to prioritize discharge, creating local quality variations that simultaneously achieve both blower efficiency and motor cooling.
2Temperature
If protrusions cover more of the openings, then motor cooling improves, but air discharge area decreases
Solution Approach 1:
The protrusions partially cover the openings rather than completely blocking them, allowing a balanced flow of air. This partial coverage is optimized to provide sufficient cooling area while maintaining adequate discharge area, achieving the right balance between motor cooling and air discharge without requiring extreme measures.
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 enhances the blower's efficiency by allowing better air discharge and motor cooling, making it suitable for both home-use and industrial-use vacuum cleaners while maintaining high performance.
Implementation Method 1
the air in centrifugal fan 117 is speeded up and runs through diffuser 121 of air guide 118, where the air is slowed down
Implementation Method 2
The air then cools rotor 105, stator 102, and the carbon brushes before the air is exhausted from exhaust port 120 of bracket 112
Data Source
AI summary
An electric blower includes a motor having a stator on which field windings are wound, a rotor facing the stator, and a bracket covering the stator and the rotor. The electric blower further includes a fan mounted to a shaft coupled to the rotor, and an air guide having a diffuser provided to the outer circumference of the fan and formed of a plurality of stationary blades adjacent to each other. The electric blower still includes a fan case having openings at its outer circumference for discharging a part of the air having passed the diffuser to the outside, and protrusions having a brim for covering a part of the openings. The foregoing structure allows the air blower to cool the motor with airflow generated by the fan.