Rotating Electrical Machine End Wall Thermal Conduction
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Solution Overview
Problem
Existing rotating electric machines face inefficiencies in cooling and heat dissipation from the interior of the housing to the outside, as the inner and outer cooling fan impellers are often separated by a distance, limiting effective heat transfer.
Innovation Solution
The first end wall of the housing, positioned between the inner and outer cooling fan impellers, is designed with high thermal conductivity (at least 100 W/m·K) and features both inner and outer cooling rib geometries, allowing for enhanced heat transfer from the inner cooling air circuit to the outer cooling air flow, with preferred materials being aluminum or aluminum alloys for improved thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the inner cooling fan impeller is disposed on the side of the stator and rotor facing towards the outer cooling fan impeller with separation by the first end wall, then the structure is stable and manufacturing is easier, but the heat transfer efficiency from the inner cooling air circuit to the outer cooling air flow is insufficient
Solution Approach 1:
The first end wall acts as an intermediary heat transfer component between the inner cooling air circuit and the outer cooling air flow. By incorporating cooling rib geometries on both sides of the end wall, it mediates heat transfer from the internal cooling circuit through the end wall to the external cooling flow, resolving the contradiction between structural simplicity and heat transfer efficiency.
Solution Approach 2:
The end wall is designed with high thermal conductivity parameters (at least 100 W/m·K) and specific cooling rib geometries to optimize heat transfer. By changing the material parameters and geometric parameters of the end wall, the heat transfer efficiency is significantly improved while maintaining the overall structural simplicity of the cooling system.
2Temperature
If the first end wall is formed with high thermal conductivity material and cooling rib geometries, then heat transfer from inner cooling air circuit to outer cooling air flow is significantly improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The end wall is designed with high thermal conductivity parameters (at least 100 W/m·K) and specific cooling rib geometries to optimize heat transfer. By changing the material parameters and geometric parameters of the end wall, the heat transfer efficiency is significantly improved while maintaining the overall structural simplicity of the cooling system.
Solution Approach 2:
Instead of making the entire housing complex, only the first end wall is designed with high thermal conductivity material and cooling rib geometries. This localized approach improves heat dissipation efficiency where most needed while keeping the rest of the housing structure simple and easy to manufacture.
3Temperature
If the inner cooling fan impeller is positioned far from the outer cooling fan impeller, then the structural design is simpler and more stable, but the heat dissipation from the interior of the housing to the outside is limited
Solution Approach 1:
The first end wall acts as an intermediary heat transfer component between the inner cooling air circuit and the outer cooling air flow. By incorporating cooling rib geometries on both sides of the end wall, it mediates heat transfer from the internal cooling circuit through the end wall to the external cooling flow, resolving the contradiction between structural simplicity and heat transfer efficiency.
Solution Approach 2:
The patent replaces the mechanical approach of directly coupling the two cooling fan impellers (which would reduce distance but increase complexity) with a thermal conduction path through the high thermal conductivity end wall. This substitution allows heat to transfer efficiently through the end wall without requiring the impellers to be in direct contact or close proximity.
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 configuration significantly improves heat transfer efficiency, effectively picking up internal heat and releasing it to the environment through the outer cooling air flow, enhancing overall cooling performance.
Implementation Method 1
an inner cooling fan impeller inside the housing, which inner cooling fan impeller upon rotation generates an inner cooling air circuit inside the housing
Implementation Method 2
the first end wall of the housing, which first end wall is disposed on the side of the outer cooling fan impeller between this cooling fan impeller and the inner cooling air circuit, is formed with a high thermal conductivity of at least 100 W/m·K
Implementation Method 3
an outer cooling fan impeller outside the housing, which outer cooling fan impeller upon rotation generates an outer cooling air flow flowing over the housing
Data Source
AI summary
A rotating electric machine (1) having a stator (4) in a housing (2) and a rotor (10) supported by a shaft (6). The housing (2) circumferential wall (12) and first and second axially opposing end walls (14, 16) support bearing flanges with bearings (18) for the shaft (6). Two cooling fan impellers (20, 22) are connected to the shaft (6). An inner cooling fan impeller (20) positioned inside the housing (2) generates an inner cooling air circuit (A) inside the housing (2). An outer cooling fan impeller (22) provided outside the housing (2), generates an outer cooling air flow (B). The first end wall (14) is formed with a thermal conductivity of at least a specified value and has an outer cooling rib geometry (28) on its outer side facing the outer cooling fan impeller (22), and an inner cooling rib geometry (30) on its opposing inner side.