Electric Machine Cooling via Axial Channels and Turbine
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Solution Overview
Problem
Existing cooling methods for electric machines, such as recirculating air cooling and internal cooling, result in significant hydraulic losses and inefficiencies, leading to reduced performance and high temperatures in active rotor parts.
Innovation Solution
A system comprising axially oriented channels through the rotor and stator with a fan and turbine arrangement, where the fan generates air flow through the channels and the turbine converts kinetic energy into rotational energy of the rotor, optimizing air cooling and reducing hydraulic losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If recirculating air cooling is used with a fan mounted on an axial end plate, then cooling effect is achieved, but large hydraulic losses occur in the flowing air
Solution Approach 1:
The patent combines the cooling function with power generation by integrating a turbine into the cooling air flow path. The turbine converts part of the kinetic energy of the cooling air into rotational energy of the rotor, thereby recovering energy that would otherwise be lost as hydraulic losses in conventional fan-only systems.
2Temperature
If internal cooling of the rotor with water or oil is implemented, then heat transfer is improved, but significant power losses occur due to hydraulic losses and mechanical seals
Solution Approach 1:
The patent uses air (a gas) instead of liquid cooling media (water or oil) to cool the rotor. This pneumatic approach eliminates the need for mechanical seals and radial shaft seals, thereby avoiding the significant power losses associated with liquid cooling systems while still achieving effective heat transfer.
3Temperature
If internal rotor cooling with liquid is used, then heat transfer to the liquid is good, but the cooling location is far from the heat generation location
Solution Approach 1:
The cooling air is generated and circulated within the rotor itself through internally mounted fans and channels. The air flows directly through the winding packs and active parts where heat is generated, eliminating the need for long external heat conduction paths and enabling self-contained cooling.
4Temperature
If a fan arrangement is used to dissipate heat losses, then cooling is achieved, but the efficiency of the electric machine is reduced
Solution Approach 1:
The patent converts the harmful effect of the fan-induced air flow (which causes efficiency reduction) into a beneficial effect by placing a turbine in the air flow path. The turbine captures the kinetic energy of the air flow and converts it into useful rotational energy, thereby offsetting the efficiency loss and even generating additional power.
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 achieves efficient cooling with minimal power loss and high efficiency, reducing temperature in rotor parts and enhancing overall performance by converting kinetic energy into rotational energy, thus improving the cooling efficiency and reducing complex liquid cooling needs.
Implementation Method 1
The at least one fan is designed to enable air to be made to flow, flowing from the first end through the at least one axially oriented channel to the second end
Implementation Method 2
The at least one turbine is designed to convert kinetic energy of the flowing air into rotational energy of the component designed as a rotor
Data Source
AI summary
A system for cooling an electric machine having two components, one of the two components rotor and the other a stator, the two components enclosing a central axis of the electric machine coaxially, The rotor during operation of the electric machine rotates relative to the stator, wherein at least one axially oriented channel passes through at least one component. A fan is arranged at a first end of the at least one channel, wherein a turbine is arranged at a second end of the at least one channel. The fan is designed to enable air to flow, flowing from the first end through the at least one axially oriented channel to the second end.