Rotating Electric Machine Dual Air Ventilation Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotating electric machines face issues where the rotor is overheated due to inside air circulation, potentially causing permanent magnet demagnetization, and the coil end part of the stator is not effectively cooled by outside air ventilation alone, leading to temperature rises.
Innovation Solution
The design incorporates a rotating electric machine structure with both inside and outside air ventilation holes to facilitate the circulation of air, allowing outside air to cool the rotor and inside air to cool the coil end part, thereby preventing temperature rises and demagnetization, and enhancing cooling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If cooling is made only by outside air ventilation, then the structure is simple, but the coil end part of the stator becomes high in temperature
Solution Approach 1:
The cooling system is segmented into two independent pathways: outside air ventilation for the rotor and inside air circulation for the stator coil end part. This allows each pathway to be optimized for its specific cooling target, preventing the coil end part from becoming overheated while maintaining structural efficiency.
Solution Approach 2:
Different cooling methods are applied to different parts of the machine: outside air ventilation is used for the rotor, while inside air circulation is used for the stator coil end part. This localized approach ensures that each component is cooled appropriately for its thermal characteristics and operational requirements.
2Device complexity
If rotor is cooled only by circulation of inside air, then the cooling structure is simple, but the inside air becomes high in temperature and the rotor temperature is raised
Solution Approach 1:
The cooling system is divided into separate pathways for the rotor and stator. The rotor is cooled by outside air ventilation, which provides a continuous supply of cool air, while the stator is cooled by inside air circulation. This segmentation prevents the rotor temperature from rising excessively.
Solution Approach 2:
Outside air ventilation is specifically applied to the rotor to provide continuous cooling with fresh air, while inside air circulation is used for the stator. This localized cooling strategy addresses the different thermal requirements of each component.
3Temperature
If both inside air circulation and outside air ventilation are used together, then cooling performance is improved, but the device complexity increases
Solution Approach 1:
The cooling system is segmented into two independent but complementary pathways: inside air circulation for the stator and outside air ventilation for the rotor. Each pathway is relatively simple in design, but together they provide comprehensive cooling performance.
Solution Approach 2:
Two cooling methods (inside air circulation and outside air ventilation) are merged into a unified cooling system that serves different parts of the machine. The combination provides superior overall cooling performance while maintaining the simplicity of each individual cooling pathway.
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 approach miniaturizes rotating electric machines, prevents permanent magnet demagnetization, and improves cooling performance, enabling the development of rail and electric vehicles with higher output power.
Implementation Method 1
cooling by circulating air inside the machine (inside air) by means of an inner fan arranged inside the machine
Implementation Method 2
cooling by ventilating air outside the machine (outside air) around the outer surface of the machine by means of an outer fan arranged outside the machine
Implementation Method 3
cooling by circulating air inside the machine (inside air)
Implementation Method 4
cooling by ventilating air outside the machine (outside air) around the outer surface of the machine
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Object Not only inside air but also coil end part of a stator 2 are prevented from becoming high in temperature, and cooling performance is improved. Solution to Problem In order to achieve the object described above, a rotating electric machine 1 of the present invention is made up of a stator 2 and a rotor 3 oppositely arranged through the intervention of predetermined air gap at the inner diameter side of the stator 2; the stator 2 has a stator iron core 4, a plurality of stator slots 12 that extend in the axial direction and are formed in the circumferential direction at predetermined intervals at the inner diameter side of the stator iron core 4, and stator coils attached in the plurality of stator slots 12; the rotor 3 has a rotor iron core 7, a plurality of rotor slots 6 that extend in the axial direction and are formed in the circumferential direction at predetermined intervals at the outer circumference side of the rotor iron core 7, and magnetic field members inserted in the rotor slots 6; and the rotor iron core 7 has an outside air ventilation hole 17a for ventilating air outside the machine and an inside air ventilation hole 16 for ventilating air inside the machine.