Fan Motor Cooling Flow Path Design to Reduce Heat and Flow Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional fan motors for handheld vacuum cleaners face challenges in balancing reduced size and weight with maintaining suction force, as high-speed rotation leads to noise, vibration, heat generation, and inefficient cooling, which compromises motor power and suction efficiency.

Innovation Solution

The fan motor design incorporates a cooling flow path structure with an air inlet on the motor mount and an air discharge opening positioned to minimize flow resistance, using atmospheric air to cool the motor without diverting motor power, and includes a mixed-flow type impeller and diffuser to optimize air flow and reduce component count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the fan motor is made lightweight to improve user convenience, then the weight is reduced, but the suction capability deteriorates due to low power

Engineering Contradiction:

Improvefan motor weightVSAvoidsuction capability

Core Design Contradiction:

Weight of moving objectVSPower

Solution Approach 1:

The patent increases the rotational speed parameter of the fan motor to compensate for the reduced weight and size. By operating at higher rotational speeds, the motor maintains sufficient suction capability despite being lightweight, thus resolving the contradiction between weight reduction and power maintenance

Inventive Principle:

Principle #35Parameter changes

2Power

If the fan motor rotates at high speed to increase power while reducing size and weight, then the power and compactness are improved, but noise, vibration and heat generation increase

Engineering Contradiction:

Improvemotor powerVSAvoidnoise, vibration and heat

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful heat generated by high-speed rotation into a beneficial cooling mechanism. The heat causes air to expand and rise, creating a natural convection current that draws cooler air through the motor housing, thereby cooling the motor internally without requiring additional cooling components or power consumption

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Temperature

If air flow is used to cool the motor, then the heat dissipation is improved, but the flow resistance at the exhaust side increases which deteriorates suction force

Engineering Contradiction:

Improvemotor coolingVSAvoidsuction force

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The patent segments the air flow paths into distinct cooling channels and suction channels. The cooling air flow path is separated from the main suction flow path, allowing cooling air to be drawn from the rear of the motor housing through dedicated cooling holes in the stator, while the suction air flows through the impeller and exits through the front. This segmentation prevents the cooling flow from creating backpressure that would reduce suction capability

Inventive Principle:

Principle #1Segmentation

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 maximizes power and suction efficiency while minimizing size and weight, reducing flow resistance and power consumption for cooling, thus enhancing overall performance and convenience.

Implementation Method 1

a cooling flow path inlet that is located at at least one of a lateral side or a lower side of the motor mount and that is configured to receive air to reduce heat generated in the motor part

Methodology Applied

Scientific EffectHeat convection: Convection

Implementation Method 2

the cooling flow path outlet is configured to discharge air from the inner space of the motor mount toward a space that is defined between the impeller and the air discharge opening based on the space between the impeller and the air discharge opening having a lower pressure than the inner space of the motor mount

Methodology Applied

Scientific EffectPressure difference: Pressure Gradient

Implementation Method 3

an air discharge opening defined at the motor mount and exposed to an outer space of the motor mount, where the air discharging opening is configured to discharge air that is suctioned through the air inlet and pressurized by the impeller

Methodology Applied

Scientific EffectImpeller compression: Impeller

Data Source

PatentUS11085454B2Fan motor having a motor mount defining a cooling flow path inlet and a diffuser body defining a cooling flow path outlet with the cooling flow path in fluid communication with the inner space of the motor mount

Publication Date: 2021.08.10 LG ELECTRONICS INC

AI summary

A fan motor for a vacuum cleaner includes a motor mount defining a cooling flow path inlet, an impeller, an impeller cover defining an air inlet, an air discharge opening defined at the motor mount and configured to discharge air to an outer space of the motor mount, and a cooling flow path outlet defined vertically above the motor mount. The cooling flow path inlet is configured to introduce air from the outer space of the motor mount into an inner space of the motor mount to cool the motor part, and the cooling flow path outlet is configured to discharge air from the inner space of the motor mount toward a space that is defined between the impeller and the air discharge opening based on the space between the impeller and the air discharge opening having a lower pressure than the inner space of the motor mount.