Rotor Pole Cooling via Thermal Conductive Sheet
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Solution Overview
Problem
Conventional air-cooled rotating machines face challenges in efficiently cooling all regions of the rotor, leading to potential overheating due to limited heat transfer through convection, especially in areas with restricted air paths, and rear ventilation solutions often compromise mechanical integrity and increase ventilation losses.
Innovation Solution
The rotor pole design incorporates gaps between the rotor coil and pole core filled with materials of higher thermal conductivity than air or insulating flanges, such as thermally conductive silicone or aluminum oxide, to enhance heat transfer by conduction, reducing thermal resistance and the need for coolant volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If air cooling through convection is used, then cooling is simple and does not require additional conduits, but heat transfer effectiveness is limited and cannot sufficiently cool all rotor regions
Solution Approach 1:
A thermal conductive sheet is introduced as an intermediary substance between the coil and pole body to facilitate heat transfer. The sheet has thermal conductivity higher than both the coil winding and pole body materials, acting as a thermal bridge to conduct heat away from the coil more effectively than air cooling alone.
Solution Approach 2:
The cooling system uses a composite approach by combining air cooling with a solid thermal conductive sheet. The sheet material is specifically selected to have thermal conductivity properties that bridge the gap between the coil and pole body, creating a hybrid cooling mechanism that overcomes the limitations of pure convection.
2Temperature
If rear ventilation with additional cooling conduits is implemented, then heat transfer coefficient and cooling surface are improved, but mechanical integrity is compromised and device complexity increases
Solution Approach 1:
The invention extracts the thermal conduction function from the mechanical structure by using a separate thermal conductive sheet. This allows heat transfer enhancement without modifying the mechanical integrity of the pole body or coil supports, avoiding the need for additional cooling conduits that would compromise structural strength.
Solution Approach 2:
The thermal conductive sheet serves as a mediator that provides the heat transfer pathway without requiring structural modifications to the rotor components. It fulfills the cooling function while preserving the mechanical integrity of the original design.
3Temperature
If cooling air flow is increased, then temperature difference and heat transfer are improved, but ventilation losses increase
Solution Approach 1:
The invention replaces part of the mechanical convection-based cooling system with a thermal conduction mechanism through the conductive sheet. This substitution reduces reliance on high-volume air flow, thereby decreasing ventilation losses while maintaining effective heat removal through conduction.
4Area of stationary object
If back cooling with additional air paths is created, then cooling surface is increased, but dust accumulation risk increases and rotor pole core is weakened
Solution Approach 1:
The thermal conduction function is extracted from the air cooling system and placed in the solid thermal conductive sheet. This eliminates the need for additional air paths between the coil and pole body, thereby preventing dust accumulation in those regions and avoiding weakening of the pole core structure.
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 improves heat dissipation through conduction, reducing temperature peaks and ventilation losses, thereby extending the service life of the machine and allowing for a more compact design with relaxed thermal constraints.
Implementation Method 1
gaps between the rotor coil and pole core filled with materials of higher thermal conductivity than air or insulating flanges, such as thermally conductive silicone or aluminum oxide, to enhance heat transfer by conduction
Data Source
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AI summary
The present disclosure relates to a rotor for a rotating machine and more in particular, the present invention relates to component of the rotor. The present disclosure generally relates to an improved cooling configuration of a rotating machine. Unlike generally known arrangements, the solution proposed herein does not guide coolant fluid to parts which require cooling. Instead, the heat generated from the losses in the rotor pole is transferred to parts having favourable characteristics for establishing heat exchange.