Passive radial supporting mechanism for primary mirror of optical telescope based on kinetic equilibrium

Abstract

The invention relates to a passive radial supporting mechanism for a primary mirror of an optical telescope based on kinetic equilibrium. One end of a first-stage connecting rod of the mechanism is hinged with the rim of a primary mirror chamber, and the other end of the first-stage connecting rod is hinged with a second-stage connecting rod and a third-stage connecting rod at the same time; the other end of the second-stage connecting rod and the other end of the third-stage connecting rod are hinged with the rim of the primary mirror; and an included angle theta is formed between the second-stage connecting rod and the third-stage connecting rod. By a kinetic equilibrium system, the radial direction of the primary mirror is not restrained by an over-restraining characteristic, so that a stable equilibrium state is realized; when temperature is changed, the whole radial supporting system does micro motion in accord with a kinetic rule by using the change of the geometric size caused by thermal deformation of a connecting rod mechanism, so that stress caused by the thermal deformation among the primary mirror, the radial supporting mechanism and the primary mirror chamber is counteracted; therefore, the passive radial supporting mechanism is suitable for supporting primary mirrors made of materials with large thermal expansion coefficients and primary mirrors working under a relatively severe working environment.

Description

technical field [0001] The invention relates to a radial support mechanism for a primary mirror of an optical telescope, in particular to a radial passive support mechanism for a primary mirror of a 1-2 meter optical telescope based on kinematic balance. Background technique [0002] The primary mirror of an optical telescope needs to maintain an accurate position and a good surface shape of the primary mirror under working conditions. The mirror support mechanism includes an axial support system and a radial support system. It is usually designed based on the principle of rigid body statics, and is realized by applying a reasonable amount of support force at an appropriate position on the back and side of the primary mirror. The support mechanism is mainly responsible for maintaining the surface shape and position accuracy of the mirror. The radial support structure also needs to offset the stress and deformation of the mirror caused by the temperature change of the working...

AI Technical Summary

Problems solved by technology

Since the positioning mechanism limits the displacement of the rigid body of the primary mirror, especially when the temperature changes in the environment, this radial support mechanism will bring greater stress and deformation to the primary mirror, so it is not suitable for applications with a large thermal expansion coefficient of its own materials. The radial support of the primary mirror, such as the new SiC material primary mirror that is currently under vigorous development; at the same time, the retrieval of prior art literature found that Hans J. Kaercher et al. in SPIE (Ground-based and Airborne Telescope III, 2010) volume 7733 Published "Mechanical principles of large mirror supports", the article pointed out that the passive mechanical floating support mechanism of the lever balance weight will enlarge the equivalent mass of the supported body, if the lever proportional coefficient is n (n is usually greater than 5 constant), then the magnification factor of the equivalent mass is (n+1) times, and the natural frequency of the system is reduced by (n+1) 1 / 2 times, which is not conducive to improving the overall rigidity of the telescope

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