Vacuum Cleaner Fan Motor Cooling Flow Path to Reduce Power Loss
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Solution Overview
Problem
Conventional fan motors for handheld vacuum cleaners face challenges in increasing power and suction force while reducing size and weight, often resulting in noise, vibration, heat generation, and reduced suction force due to high-speed rotation, which also increases flow resistance and power consumption for cooling.
Innovation Solution
The fan motor structure incorporates a cooling flow path that utilizes atmospheric air to cool the motor part, minimizing power reduction and suction force loss by arranging the air discharge opening close to the impeller and using natural air flow generated by the impeller, thereby reducing the number and size of components and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the fan motor rotates at high speed to increase power and reduce size, then power and suction force are improved, but noise, vibration, and heat generation increase
Solution Approach 1:
The patent applies dynamic balancing to the impeller by adjusting the position and amount of balancing weights on the impeller hub, allowing the rotor to operate stably at high speeds. This dynamic adjustment reduces vibration and noise while maintaining the high rotational speed needed for increased power output.
Solution Approach 2:
The patent changes the rotational speed parameter of the motor, operating it at speeds exceeding 50,000 rpm to increase power output while reducing the physical size of the motor. This parameter change is compensated by improved balancing to mitigate the negative effects of high-speed rotation.
2Power
If the fan motor rotates at high speed to increase power, then power and suction force are improved, but heat generation increases requiring power to be used for cooling
Solution Approach 1:
The patent implements self-service cooling where the motor's own rotation drives the cooling process. The motor rotor's rotation creates airflow through the cooling passages in the stator and rotor, eliminating the need for separate cooling fans or external cooling systems. The motor serves both its primary function of driving the impeller and its secondary function of cooling itself through the same rotational motion.
3Temperature
If air flow is used to cool the motor directly, then cooling is achieved, but flow resistance increases and suction force deteriorates
Solution Approach 1:
The patent segments the airflow paths into separate channels: one for suction air entering through the air inlet and another for cooling air entering through cooling air inlets. This segmentation allows cooling air to flow through internal passages without mixing with or blocking the suction air path, maintaining suction performance while achieving effective motor cooling.
Solution Approach 2:
The patent introduces cooling air as an intermediary substance that transfers heat from the motor components. The cooling air flows through dedicated cooling passages in the stator and rotor, absorbing heat and carrying it away, thus cooling the motor without requiring the suction air to be diverted for cooling purposes.
4Weight of moving object
If the fan motor size is reduced to decrease weight, then portability is improved, but power and cooling capability may be compromised
Solution Approach 1:
The patent changes the operational parameters of the motor, specifically increasing the rotational speed to exceed 50,000 rpm. This allows the motor to produce the required power output with a smaller physical size, thereby reducing weight while maintaining or even increasing power capability. The high-speed operation is made viable through improved balancing techniques.
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, suction force, and suction efficiency while minimizing flow resistance and power consumption, allowing for a more compact and lightweight fan motor with effective cooling without additional components or motor power usage.
Implementation Method 1
a fan which is rotated by the motor to generate an air flow
Implementation Method 2
a cooling flow path that utilizes atmospheric air to cool the motor part
Data Source
Figure 1
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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.