Separable Roller Screw Assembly for Low-Shock Spacecraft Release
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Solution Overview
Problem
Current spacecraft separation systems face challenges in ensuring safe and controlled separation of spacecraft elements during launch and orbital phases, with existing solutions often introducing additional risks and energy losses due to inefficient separation mechanisms.
Innovation Solution
A separable roller screw assembly featuring a planetary roller arrangement with rotatable rollers and a nut module, allowing for axial displacement and rotation to manage loads and separation with reduced shock and increased reliability, utilizing rolling friction to enhance control and energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pyrotechnic fasteners or pneumatic systems are used for separation, then separation can be initiated, but additional risks are introduced into the success of the launch mission
Solution Approach 1:
The patent replaces pyrotechnic fasteners and pneumatic systems with a purely mechanical roller screw assembly. The separation is achieved through mechanical rotation of the roller screw, which converts rotational motion into axial displacement to release the clamp band. This eliminates the need for pyrotechnic or pneumatic systems, thereby reducing additional risks while maintaining reliable separation initiation.
2Productivity
If conventional separation mechanisms are used, then separation occurs, but energy losses increase due to inefficient separation mechanisms
Solution Approach 1:
The roller screw assembly utilizes periodic rotation to achieve separation. The clamp band is released through controlled rotational cycles of the roller screw, which periodically engage and disengage the threaded sections. This periodic mechanical action provides efficient energy transfer and control during the separation process, reducing energy losses compared to conventional mechanisms.
3Speed
If separation is performed quickly, then separation speed increases, but shock and disturbance levels increase
Solution Approach 1:
The roller screw assembly provides dynamic control over the separation process. By controlling the rotation speed and acceleration of the roller screw, the system can achieve rapid separation while managing the forces involved. The threaded engagement of the roller screw with the clamp band allows for controlled energy dissipation, reducing shock and disturbance even at higher separation speeds.
4Ease of operation
If threaded sections are used to connect fitting parts, then detachable connection is provided, but separation control precision decreases
Solution Approach 1:
The roller screw acts as an intermediary mechanism between the control system and the clamp band release. Instead of directly actuating the threaded sections, the roller screw converts rotational motion into precise axial displacement through its threaded engagement with the clamp band. This intermediary mechanism provides both ease of operation through rotation and precise control over the separation timing and displacement.
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 separable roller screw assembly improves the control and reliability of spacecraft separation by minimizing shock and energy losses, enabling precise axial displacement and load management, thus enhancing the safety and efficiency of spacecraft separation processes.
Implementation Method 1
utilizing rolling friction to enhance control and energy efficiency
Data Source
AI summary
The present disclosure relates to a separable roller screw assembly comprising: a first screw shaft having a first external thread and being axially separated from a second screw shaft having a second external thread; a planetary roller arrangement comprising multiple rotatable rollers radially arrayed about the first and second screw shafts, whilst being encapsulated by a rotatable nut module; the rotatable nut module being coaxially arranged about the first and second screw shafts and configured for maintaining the planetary roller arrangement, the first and second screw shafts in an axially fixed configuration to permit the assembly to carry a load in an axial direction corresponding to an axial tensile force, whilst enabling displacement of the first screw shaft relative to the second screw shaft when said assembly is released from said axially fixed configuration; and wherein each one of the multiple rollers comprises first and second roller external thread regions adapted to engage said first external thread and said second external thread, respectively. Moreover, the present disclosure relates to a space craft release mechanism for separating a first space craft element from a second space craft element and comprising a separable roller screw assembly. In addition, the present disclosure relates a clamp band system for a load bearing interface assembly of a space craft comprising a separable roller screw assembly.