Brushless Starter-Generator Power Module With Integrated MOSFET Cooling
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Solution Overview
Problem
Starter-generator machines with commutators and brushes experience wear, necessitating frequent overhauls, and replacing them with MOSFETs introduces space and cooling challenges, along with the need for additional components that increase weight and complexity.
Innovation Solution
A brushless starter-generator design with MOSFETs housed within a single housing, utilizing a shaft sensor to control MOSFET switching, a chassis for heat dissipation, and phase change material for thermal management, maintaining the same outer diameter as traditional machines to simplify installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MOSFETs are used to replace commutators and brushes for switching function, then overhaul intervals are extended and reliability is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent combines the MOSFET power module, control electronics, and cooling system into a single integrated housing that replaces the traditional commutator-brush assembly. This merging of components achieves the switching function without requiring separate external electronics boxes and heavy high-current wires, thereby extending overhaul intervals while avoiding increased device complexity.
2Reliability
If MOSFETs are used to replace commutators and brushes, then switching function is improved, but heat generation increases requiring additional cooling
Solution Approach 1:
The patent introduces a thermal paste intermediary between the MOSFETs and the housing to efficiently transfer heat. This thermal interface material acts as a mediator that conducts heat away from the MOSFETs to the housing structure, which then dissipates the heat to the surrounding environment, thereby managing the increased heat generation from the electronic switching components.
3Reliability
If separate box housing is used for electronics, then MOSFETs are protected, but additional space and weight are required
Solution Approach 1:
The patent merges the protective housing function with the existing starter-generator structure. Instead of adding a separate external electronics box, the MOSFETs and control electronics are housed within the existing housing structure, eliminating the need for additional protective enclosures and heavy high-current wiring connections, thereby achieving component protection without increased weight.
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
Extends overhaul intervals, reduces weight and complexity, and efficiently cools MOSFETs, ensuring reliable operation without additional space or heavy wiring.
Implementation Method 1
a first portion of the chassis between the cover and the MOSFETs comprises a phase change material
Data Source
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AI summary
A rotating machine assembly includes a rotating machine that has a cover that defines an outer surface of the rotating machine and a stator disposed within the cover. The stator is stationary with respect to the cover. The rotating machine also includes a shaft rotatably disposed at least partially within the cover so as to define a rotation axis. The shaft Includes a first end that is connectable to an aircraft engine and a second end that is opposite the first end. The rotating machine also includes a rotor attached to the shaft, the rotor being movable with respect to the stator and a power module including at least one MOSFET that periodically reverses an electrical current direction of the rotor. The power module includes the at least one MOSFET Is disposed within the cover.