Axial Flux Motor Torque-Isolation for Fault-Tolerant Aircraft Drive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric motors for aircraft are not reliable and efficient, and there is a need for fault-tolerant designs that can continue operation despite faults such as open circuits, short circuits, or mechanical failures.
Innovation Solution
An axial flux electric motor with two motor sections, each rotor secured to a common axle via breakable connecting elements, allowing one section to continue operating even if the other experiences a fault, with each section being electrically, magnetically, and thermally isolated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single motor section is used, then the device complexity is reduced, but the reliability decreases because a fault causes complete failure
Solution Approach 1:
The motor is divided into two independent motor sections, each with its own stator, rotor, and connecting elements. This segmentation allows one section to continue operating if the other fails, thereby improving reliability without requiring a completely redundant dual-motor system.
Solution Approach 2:
The connecting elements are designed to dynamically respond to fault conditions by breaking when excessive relative torque is detected. This dynamic failure mode allows the system to transition from a two-section configuration to a single-section configuration, maintaining operation despite damage.
2Reliability
If connecting elements are made stronger to prevent breakage, then the strength increases, but the reliability decreases because faults cause complete failure
Solution Approach 1:
The connecting elements are pre-designed with a specific strength threshold that acts as a protective mechanism. When excessive torque occurs, these elements break as intended, cushioning the system from complete failure by allowing one motor section to continue operating independently.
Solution Approach 2:
The potential harm of connecting element failure is converted into a benefit by designing the failure mode to be controlled and localized. When elements break, they enable the surviving motor section to continue operation, transforming what could be a catastrophic failure into a manageable fault condition.
3Reliability
If electrical, magnetic, and thermal isolation is implemented between motor sections, then the fault tolerance improves, but the device complexity increases
Solution Approach 1:
The motor is segmented into two electrically, magnetically, and thermally isolated sections. This segmentation prevents fault propagation between sections through physical and field-based isolation, allowing independent operation of each section while maintaining overall system functionality.
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
The design ensures continued operation of the motor despite faults, reducing the risk of complete failure and maintaining aircraft functionality, while potentially reducing weight and envelope size.
Implementation Method 1
An axial flux electric motor has a rotor and a stator that are spaced axially from each other. The rotor and the stator are thus spaced from each other along the common axle of the axial flux electric motor. An axial flux electric motor is arranged to generate a magnetic flux that is aligned substantially parallel to the common axle and thus to the axis of rotation of the rotors.
Data Source
AI summary
An axial flux electric motor for an aircraft includes a first motor section having a first stator and a first rotor, and a second motor section having a second stator and a second rotor. The first and second rotors are mounted on a common axle. The first rotor is secured to the common axle by a first set of connecting elements. The second rotor is secured to the common axle by a second set of connecting elements. The first set of connecting elements is arranged to break when the relative torque between the common axle and the first rotor is greater than a first particular threshold. The second set of connecting elements is arranged to break when the relative torque between the common axle and the second rotor is greater than a second particular threshold.