Generator Disconnect Mechanism With Retractable Nested Shaft
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Solution Overview
Problem
Existing disconnect devices for aircraft generators are unreliable, require complex arrangements, occupy too much space, and can cause mechanical damage due to rotating parts within the generator housing, and are susceptible to lubrication failures.
Innovation Solution
A generator with a translatable drive connection that allows the second shaft to be partially retracted outside the housing, using a translatable drive connection and actuation means to disconnect the mechanical drive input, ensuring no driven rotating parts remain inside the generator upon disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the disconnect device is located within the generator housing, then the disconnect mechanism can be integrated, but driven rotating parts remain inside the generator causing mechanical damage and lubrication issues
Solution Approach 1:
The disconnect mechanism is extracted from the generator housing and located externally. The second shaft is at least partially disposed outside the housing, allowing the disconnect mechanism to operate outside the generator housing. This extraction eliminates the harmful effects of rotating parts remaining inside the generator during disconnection, preventing mechanical damage and lubrication failures while maintaining integration through the translatable drive connection.
2Object-affected harmful factors
If a translatable drive connection is used to retract the second shaft outside the housing, then no rotating parts remain inside upon disconnection, but the device requires more space for the translatable connection
Solution Approach 1:
The second shaft is nested within the first shaft, with the translatable drive connection arranged within the hollow interior of the first shaft. This nesting arrangement allows the translatable drive connection to occupy the internal volume of the first shaft rather than requiring additional external space, efficiently utilizing the existing generator structure while enabling the second shaft to be retracted outside the housing for disconnection.
3Reliability
If complex arrangements with numerous moving parts are used, then the disconnect mechanism can be robust, but it occupies too much space for smaller-scale generators
Solution Approach 1:
The disconnect mechanism is segmented into distinct functional components: the first shaft connected to the rotor, the second shaft at least partially disposed inside the first shaft, the translatable drive connection enabling relative movement, and the actuation means. This segmentation allows each component to be optimized for its specific function while maintaining overall compactness, achieving robustness through well-defined functional elements rather than numerous moving parts.
Solution Approach 2:
The second shaft is nested within the first shaft, and the translatable drive connection is arranged within the hollow interior of the first shaft. This nested arrangement minimizes the volume occupied by the disconnect mechanism, making it suitable for smaller-scale generators while maintaining reliability through the well-defined functional components of the segmented design.
4Ease of operation
If axial force is applied to move the second shaft for disconnection, then the disconnect mechanism can operate, but the axial force may be insufficient in certain failure scenarios
Solution Approach 1:
The translatable drive connection acts as an intermediary mechanism between the actuation means and the second shaft. It enables the transfer of axial force while allowing relative movement between the first and second shafts, providing a mechanical advantage that amplifies the axial force applied by the actuation means. This intermediary arrangement ensures sufficient force is transmitted to reliably disconnect the drive connection even in failure scenarios where high force is required.
Data Source
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AI summary
The present invention relates to a generator comprising a rotor, an inner shaft, an outer shaft, and an actuation means. The outer shaft is connected to the rotor so as to transfer a torque to or from the rotor. The inner shaft is at least partially disposed inside the outer shaft. The inner shaft is coupled to the outer shaft by means of a translatable drive connection. The actuation means is configured to actuate the second shaft towards a retracted position. The translatable drive connection is configured to allow a transfer of torque between the first and second shafts, and enables movement of the second shaft, relative to the first shaft, along its axis of rotation from an extended position to a retracted position, such that an input portion of the second shaft can be at least partially retracted in a retraction direction towards the rotor upon activation of the actuation mechanism. A disconnect mechanism disposed on the second shaft can therefore be disconnected upon retraction of the second shaft.