Satellite Boom Hinge Actuator Using Pre-Buckling Drive Chain
Solution Overview
Problem
Traditional hinge actuators for spacecraft booms face challenges with structural integrity and efficiency, particularly when large rotation angles are required, as they need longer links that pass through slots, reducing structural integrity and increasing complexity and cost.
Innovation Solution
A flex-drive actuator using a drive chain with links that pre-buckle into a rigid circular arc, allowing for scalable actuation angles and improved structural integrity by converting the chain into a rigid gear segment, which can be stored compactly when not in use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional linkage actuators are used for large rotation angles, then the actuation capability is improved, but the links become longer and must pass through slots, reducing structural integrity
Solution Approach 1:
The patent employs a flexible chain with rigid links that can bend to accommodate large rotation angles while maintaining structural integrity. The chain links are designed with pinned connections that allow flexibility during deployment, eliminating the need for long rigid links that would compromise boom strength.
Solution Approach 2:
The actuator transitions from a static rigid linkage to a dynamic flexible chain system. The chain can change its configuration during deployment, adapting its shape to achieve large rotation angles without requiring links that span the entire deployment distance, thus preserving boom structural integrity.
2Adaptability or versatility
If link length is increased to achieve larger rotation angles, then the actuation range is improved, but the efficiency decreases and complexity increases
Solution Approach 1:
The actuator is segmented into multiple rigid chain links connected by pinned joints, allowing the system to achieve large rotation angles through cumulative small movements of individual links. This segmentation avoids the need for single long links, reducing complexity while expanding actuation range.
Solution Approach 2:
The chain mechanism introduces an additional degree of freedom by allowing the links to articulate relative to each other, transforming the actuation from a single-degree-of-freedom rigid linkage to a multi-degree-of-freedom flexible chain, thereby achieving larger ranges with simpler individual components.
3Ease of operation
If slots are provided in boom and hinge body for link passage, then the actuation mechanism is enabled, but the structural integrity is reduced to unacceptable levels
Solution Approach 1:
The invention extracts the flexibility requirement from the boom structure itself and relocates it to the chain mechanism. By taking out the need for slots from the boom and hinge bodies, the structural integrity of these critical load-bearing components is preserved while the chain provides the necessary articulation capability.
Data Source
AI summary
A flex-drive actuator for a satellite boom hinge or other hinge applications. Using a motor-driven cog and a unique drive chain, the hinge can be reversibly driven between open and closed positions, thereby deploying or stowing the boom and attached payload. The chain includes links designed so that, when bent in one direction, the chain pre-buckles into a rigid circular arc form that matches the deployment path of the hinge. This pre-buckling essentially converts the chain into a rigid gear segment that can carry a moment to actuate the hinge. As the cog retracts the chain and the hinge closes, the circular shape of the chain de-buckles on the free side of the cog, where the chain can be stored as a straight section inside of a boom tube or folded into a magazine. The flex-drive actuator can accommodate any desired actuation angle by addition of links to the chain.