Split type bi-material flexible mechanism of space-based large-calibre high-facial-contour-precision reflector assembly

Abstract

The invention, which belongs to the technical field of spatial remote sensing, relates to a split type bi-material flexible mechanism of a space-based large-calibre high-facial-contour-precision reflector assembly. The provided flexible mechanism is formed by an invar flange plate and a titanium-alloy flexible link. Flatness of a twenty-first flange surface and a twentieth flange surface of the invar flange plate is higher than 0.005mm and depths of parallelism of the twenty-first flange surface and the twentieth flange surface of the invar flange plate are not lower than 0.008mm. The titanium-alloy flexible link has a structure with three claws distributed around the periphery uniformly at 120 degrees; three radial flexible grooves and two axial flexible grooves are formed in each claw; flatness of a thirteenth flange plane and a nineteenth flange plane of the titanium-alloy flexible link is higher than -.005mm and depths of parallelism of the thirteenth plane and the nineteenth plane of the titanium-alloy flexible link are not lower than 0.008mm; and the thirteenth flange plane is formed by three small planes. The invar flange plate and the titanium-alloy flexible link are connected by connection of the thirteenth flange plane and the twenty-first flange surface with twelve bolts six cylindrical pins, thereby forming the flexible mechanism. According to the flexible mechanism provided by the invention, the influence on the facial contour precision by a thermal load and an assembling error is reduced substantially; and the anti-facial-contour-changing performance under a gravitational load is optimized.

Description

technical field [0001] The invention belongs to the technical field of space remote sensing, and in particular relates to a split-type dual-material flexible joint applied to a space-based large-diameter and high-surface-precision reflector assembly passively supported by three points on the back. Background technique [0002] Space remote sensors are used to conduct general surveys and detailed surveys of earth and space resources, and their applications in fields such as earth observation and space exploration have important scientific and economic significance. The optical elements in the remote sensor, especially the large-aperture mirror, are the most important components in the entire optical system, and its surface shape accuracy is directly related to the imaging quality of the entire remote sensor. [0003] The surface shape accuracy error of the mirror mainly includes the processing residual error of the mirror surface, the surface shape error caused by the gravity...

AI Technical Summary

Problems solved by technology

[0007] The disadvantages of this structure are: (1), the fifth flexible groove 5 and the sixth flexible groove 6 are vertically arranged, and the stiffness characteristics of the flexible joint 4 are not circumferentially symmetric around the axis of the flexible joint 4, in order to ensure uniform weakening of thermal stress and Assembling stress, the three flexible joints 4 are arranged rotationally symmetrically around the optical axis 120 of the primary mirror. In this way, when the optical axis is horizontal to bear the gravity load, the stiffness of the three flexible joints 4 in the direction of gravity is inconsistent, and the deformation is not coordinated. The three flexible joints bear The inconsistency of the gravity of the mirror will lead to the internal stress of the mirror body, resulting in a large surface error caused by the gravity load of the mirror assembly. Of course, this effect is not great, but for large-diameter mirrors that require high-precision surface shape For components, it is more obvious; (2), when the mirror assembly is subjected to temperature loads, the flexible joint 4 weakens the thermal stress caused by the inconsistency of the thermal expansion coefficient of the mirror body with the back plate and the connection structure of the back plate, but this flexible joint The ability of 4 to weaken the thermal stress is limited. When the surface accuracy of the mirror assembly is not high, the flexible joint 4 can meet the use requirements, but for the mirror assembly with high surface accuracy requirements, this flexible joint The residual thermal stress after weakening in Section 4 cannot be ignored, especially for large aperture mirror components

Images