Electric Motor Cooling with Bleed Air and Integrated Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High power density electric motors for aircraft and mobile applications require effective cooling solutions, as traditional methods like heat exchangers and heat pipes are insufficient for efficient heat dissipation.
Innovation Solution
An electric motor assembly utilizing bleed air as a primary coolant, where the air is accelerated by the propulsion system and used to create a radially outward coolant flow, with a channel system and integrated heat exchanger within the stator housing to dissipate heat efficiently, and a rotor design that generates coolant flow during rotation for compact and efficient cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If traditional heat exchangers or heat pipes are used for cooling, then cooling function is provided, but the motor size and weight increase, reducing power density
Solution Approach 1:
The cooling device is integrated into the motor structure, merging the cooling function with the motor housing and rotor components. The stator housing serves dual purposes as both structural enclosure and cooling channel housing, while the rotor combines magnetic means with coolant flow generation structures, eliminating separate cooling system weight
Solution Approach 2:
The rotor's rotation itself generates the coolant flow through centrifugal force and the shaped structures (spokes, aerofoil devices), eliminating the need for external pumps or motors to drive the cooling fluid. The system uses its own operational motion to provide the cooling function
2Temperature
If traditional heat exchangers or heat pipes are used for cooling, then cooling function is provided, but the motor volume increases, reducing power density
Solution Approach 1:
The cooling channels are nested within the existing motor structure - channels are formed in the stator housing walls and rotor components, utilizing the hollow spaces and structural volumes already present in the motor design rather than adding external cooling components
Solution Approach 2:
The cooling device is integrated into the motor structure, merging the cooling function with the motor housing and rotor components. The stator housing serves dual purposes as both structural enclosure and cooling channel housing, while the rotor combines magnetic means with coolant flow generation structures, eliminating separate cooling system volume
3Power
If high power density is achieved, then power output increases, but heat generation increases requiring more complex cooling
Solution Approach 1:
The rotor's rotation itself generates the coolant flow through centrifugal force and the shaped structures (spokes, aerofoil devices), eliminating the need for external pumps or motors to drive the cooling fluid. The system uses its own operational motion to provide the cooling function
Solution Approach 2:
The system uses fluid dynamics principles where the rotating rotor structures (spokes, aerofoil-like devices) generate airflow or coolant flow through their shape and rotation, utilizing aerodynamic/hydrodynamic forces to circulate the cooling medium without mechanical pumps
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 solution provides a compact and efficient cooling method that leverages available, fresh, and clean bleed air to effectively cool the motor components, enhancing power density and reducing the motor's size, especially in the radial direction.
Implementation Method 1
The stator winding and the magnetic means are formed and arranged so that they interact electromagnetically with each other via an air gap formed between them
Implementation Method 2
the rotor has essentially radially oriented spokes, wherein the spokes are formed to generate the coolant flow during rotation of the rotor
Implementation Method 3
A heat exchanger is integrated in or on the stator housing, wherein the channel system is arranged and formed in such a way that at least part of the primary coolant can be fed to the heat exchanger
Data Source
AI summary
The invention relates to an electric motor with an integrated cooling device, which uses in particular bleed air as the primary coolant for cooling components of the stator and/or the rotor. Ambient air accelerated by the propulsion means, for example by a propeller, that is driven by the electric motor is used here as the bleed air. A channel system is integrated within the stator housing that has one or more channels for the targeted feed of the primary coolant to the component to be cooled. In the case of cooling the stator, a heat exchanger is also integrated within the stator housing, for example an annular heat exchanger that is arranged coaxially with respect to the stator and to which the primary coolant is fed. For cooling the rotor, a coolant passage is provided that also includes the air gap of the electric machine, for example.