Multi-segment split spool for redundant spacecraft release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing release apparatuses, such as separation spool devices, face issues with unpredictable dynamics, fouling, geometric limitations, and friction lock-up, which can prevent the successful deployment of spacecraft elements like solar arrays, and lack mechanical redundancy to ensure release even in case of mechanical failure.
Innovation Solution
A multi-segment split spool with overlappingly wound tensioned tapes that require less radial motion for release, providing predictable unwinding dynamics and mechanical redundancy by allowing release with either one of the wound tapes, thereby reducing the risk of failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wire is wrapped under tension around the outside of the spool to hold two pieces together, then the spool segments are restrained, but the wire may have unpredictable dynamics when released and may foul upon itself preventing release
Solution Approach 1:
The spool is divided into multiple segments (at least two) that can separate from each other during release. Each segment is restrained by its own tensioned tape, allowing independent control and predictable unwinding dynamics without the fouling issues of a single wrapped wire.
Solution Approach 2:
The restraining function is extracted from a single wrapped wire to separate tensioned tapes that wrap around individual spool segments. This extraction allows each tape to be independently controlled and released, eliminating the unpredictable dynamics and fouling problems of the wrapped wire design.
2Device complexity
If a two piece split spool design is used, then the spool can be held together with a wire, but significant radial movement is required for release and geometric limitations reduce load carrying capacity
Solution Approach 1:
The spool is segmented into multiple sections that can separate axially with minimal radial movement. The tensioned tapes restrain the segments in the axial direction, allowing the segments to move apart axially during release without requiring significant radial motion.
Solution Approach 2:
The restraining and release mechanism transitions from radial motion to axial motion. The tensioned tapes constrain segments axially, and release occurs through axial separation of segments rather than radial movement, fundamentally changing the dimension of operation.
3Device complexity
If a two segment spool is used, then the structure is simple, but friction lock-up condition occurs due to friction between spool-to-captured member interface preventing release
Solution Approach 1:
The spool is divided into multiple segments with tensioned tapes restraining each segment. This segmentation distributes the load and reduces friction at each interface, preventing friction lock-up while maintaining structural simplicity through modular design.
Solution Approach 2:
The tensioned tapes are pre-installed and tensioned around the spool segments before operation. This preliminary action ensures that the segments are properly restrained and positioned, preventing friction lock-up conditions from developing during operation.
4Reliability
If mechanical redundancy is added to allow release in case of failure, then release reliability improves, but device complexity increases
Solution Approach 1:
The spool is segmented into multiple sections with independent tensioned tapes, creating inherent mechanical redundancy. If one tape or segment fails, the other segments and tapes can still function to achieve release, providing failure resistance without requiring additional redundant mechanisms.
Data Source
AI summary
A redundant release apparatus having a multi-segment split spool with a central bore adapted to axially restrain a tensioned member. Two tensioned tapes are overlappingly wound around the spool segments thereby preventing radial movement of the spool segments. Overlapping winding design of each of the tapes provide predictable unwinding dynamics upon release. The multiple segments require less radial motion for release of the tensioned member.