New Construction Solutions of Gear Using in Space Vehicle Control Systems

Abstract

Outer space presents construction challenges that are completely different from the terrestrial environment. They should be characterized by high resilience and indefinite durability because there is no possibility of repair during exploitation. There are drives in spacecraft control systems that are necessary to move solar panels, robotic arms, and manipulators, and also to position antennas. In these devices, they have applications where harmonic drives are characterized by high kinematic accuracy but relatively low mechanical strength. The analysis presented in this study is aimed at modifying the shape of the harmonic drive to increase its durability and reliability. In this study, the most vulnerable damage element of the harmonic drive is the flexspline. The calculation was carried out using the finite element method (FEM) in the computer program ABAQUS. A standardized shape was tested as a basic model, and several other design solutions were proposed. For each of them, the mechanical strength was determined, which allowed the selection of the most preferred shape for the flexspline of the harmonic drive. The specific environmental requirements of the expectations for sand for gear used in spacecraft control systems were included in the analysis. The selected construction solutions of the flexspline allow for longer work and transfer of greater loads by the harmonic driver than the solutions currently used. The choice of harmonic driver design shape allows for failure-free and maintenance-free work in space vehicle control systems.