External Rotor Fan Cooling Channel Without Active Cooling Wheels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing external rotor motor fans face challenges in cooling efficiency at low speeds and noise generation at high speeds, with active cooling wheels being insufficient and costly, while passive cooling methods increase weight or cost.
Innovation Solution
A fan design with a continuous cooling channel that utilizes a pressure difference generated by the fan wheel to create a passive cooling airflow, effectively cooling both motor electronics and drive components without active cooling wheels, thereby reducing noise and material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an active cooling wheel is installed on the rotor to cool motor electronics, then cooling capacity is improved, but noise is generated at high speeds and additional torque is required reducing efficiency
Solution Approach 1:
The harmful active cooling wheel is extracted and removed from the system. Instead, a passive cooling channel is integrated into the motor structure that utilizes the existing fan-generated pressure difference to cool the motor electronics without any additional moving parts or noise generation.
Solution Approach 2:
The cooling system serves itself by utilizing the pressure difference already generated by the fan for its primary function. The fan's operation naturally creates a pressure gradient that drives cooling airflow through the electronics housing, eliminating the need for separate active cooling mechanisms.
2Temperature
If an active cooling wheel is installed on the rotor to cool motor electronics, then cooling capacity is improved, but additional torque is required reducing efficiency
Solution Approach 1:
The energy-consuming active cooling wheel is extracted and removed. The passive cooling channel replaces it, utilizing the fan's existing pressure generation without requiring additional torque or energy input.
Solution Approach 2:
The cooling system utilizes the fan's own operational byproduct (pressure difference) to drive cooling airflow, making the system self-sufficient without additional energy requirements.
3Temperature
If the surface area of adjacent components is increased or wall thickness is increased to absorb more heat, then cooling capacity is improved, but weight increases
Solution Approach 1:
Instead of adding material mass for heat absorption, the solution uses fluid dynamics (airflow through cooling channels) to transfer heat away from critical components. The pressure-driven airflow efficiently removes heat without requiring increased component mass or wall thickness.
4Temperature
If materials with higher thermal conductivity are used to improve heat dissipation, then cooling capacity is improved, but manufacturing cost increases
Solution Approach 1:
Instead of relying on expensive high-conductivity materials, the invention uses engineered airflow channels to achieve heat dissipation. This approach maintains standard materials while improving cooling through optimized fluid flow paths that efficiently remove heat from electronics and drive components.
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 solution provides efficient cooling at low speeds with reduced noise and material costs, enhancing the overall performance and longevity of external rotor motor systems.
Implementation Method 1
the fan generates a pressure difference between its suction side, preferably associated with the rotor, and its pressure side, preferably associated with the motor electronics, via the fan wheel
Implementation Method 2
a cooling airflow through the cooling channel can be generated exclusively passively by the pressure difference created by the fan wheel in order to cool both the electronics section and the motor section
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a fan with an external rotor motor comprising a motor section and an electronics section, wherein the motor section and the electronics section are arranged axially adjacent to each other along the axis of rotation, wherein the fan, in its intended operation, generates a pressure difference between its suction side, preferably associated with the rotor, and its pressure side, preferably associated with the motor electronics, via the fan wheel, wherein a continuous cooling channel runs within the external rotor motor from a pressure-side inlet opening and at least sectionally along the rotor to a suction-side outlet opening, and in operation a cooling airflow through the cooling channel can be generated exclusively passively by the pressure difference generated by the fan wheel.