Rotating Machine Casing With Segmented Contact Fins
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Solution Overview
Problem
Rotating electrical machines face challenges in maintaining uniform temperature distribution along the stator due to limited contact points between the casting and stator, leading to inefficient heat exchange and increased acoustic noise, especially in high-power machines where radial ventilation channels are costly and complex to implement.
Innovation Solution
The introduction of a casting design with a system of contact fins of varying lengths, including continuous, medium, and short length fins, which increases the heat exchange area and standardizes temperature distribution by enhancing thermal energy removal through a bilateral ventilation system, eliminating the need for radial air flow channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the number of contact points between casting and stator is increased, then heat exchange efficiency is improved, but device complexity increases
Solution Approach 1:
The casting internal surface is segmented into multiple contact points with the stator, each equipped with fins of varying lengths. This segmentation allows heat to be extracted at multiple locations along the stator length, improving temperature uniformity without requiring complex radial ventilation channels.
Solution Approach 2:
Instead of using radial ventilation channels that extend through the stator length (adding complexity in one dimension), the invention adds heat exchange surface area in another dimension by attaching fins to the casting internal surface at multiple contact points. This transforms the heat exchange approach from internal stator channels to external casting surface fins.
2Temperature
If cooling fluid outflow is increased to remove more thermal energy, then heat exchange efficiency is improved, but acoustic noise increases
Solution Approach 1:
The heat exchange process is segmented into multiple contact points along the stator length, allowing thermal energy to be removed progressively along the cooling fluid path rather than requiring high-velocity flow through a single channel. This reduces turbulence and associated acoustic noise.
Solution Approach 2:
The invention adds heat exchange surface area through fins extending from the casting internal surface, creating additional heat transfer pathways perpendicular to the cooling fluid flow direction. This increases the heat exchange coefficient without requiring increased fluid velocity, thereby reducing acoustic noise.
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 effectively increases thermal energy removal and maintains uniform temperature distribution within the stator and coils, reducing acoustic noise and production complexity while maintaining efficient heat exchange.
Implementation Method 1
The main physical mechanism by which the thermal energy of the machine components migrates to the cooling fluid is called forced convection and basically depends on the surface in contact with the cooling fluid and on this fluid speed on the surface
Implementation Method 2
The thermal energy contained in the stator, whether it has been generated or conducted for this, is basically dissipated by the cylindrical shell surface of the same. The only way to remove the heat by the outflow of the cooling fluid passing between the casting and the external diameter of the stator is through the stator cylindrical shell surface and through the little contact area between the stator and the casting; latter, through the conduction mechanism.
Data Source
Figure 1~2
Figure 3A~3B
Figure 4A~4B
AI summary
The present patent of the invention relates to a casting for electrical rotating machines, preferably for open drip-proof machines type, granted by a greatest number of contact elements between the casting and the stator, these elements being fins with different lengths, arranged in its interior, so that to increase the heat exchange efficiency between the assembly stator/casting and the cooling fluid, maintaining an uniform temperature distribution along the length of the stator and coils.