Linear rolling guide have widely used in precision machinery today, with significant advantages such as high precision, low traction and low wear. Research on the dynamic characteristics of precision linear rolling guide became very important for space applications due to the continuous improvement of the manufacturing level of high-precision equipment. The THK's RSR small precision guide is studied in this research. The model of guide joint is established by optimized tandem damping element with the finite element method to simulate the dynamic stiffness and ball mass of the guide joint. The analytical formula based on Hertzian contact theory is adopted in this research to obtain the dynamic parameters of the guide joint. Accomplishing the the dynamic simulation analysis of the precision guide based on the finite element method by MSC.Patran & Nastran software.
In this paper, a new type of focusing mechanism for space telescope is designed to compensate defocusing caused by alteration of space condition in orbit. The focusing mechanism is driven by a stepping motor and a worm gear reducer, transmitted by a ball screw and output by a flexible hinge. It has advantages of low mass, small overall size and especially high accuracy that is better than 1 micrometer. As one of main parts of focusing mechanism, the flexible hinge is mounted in the focusing shaft and connected to the nuts of ball screw kinematic pair which has mechanical end stops. The focusing shaft is guided by two couples of thin film boards to ensure the precise displacement along optical axis direction. The secondary mirror frame is connected to the shaft to complete focusing. Firstly, the focusing mechanism is designed, and the design scheme is illustrated in this paper. Then a modal analysis with finite element method for the mechanism is completed. The results show that the dynamic stiffness is high enough and meets the requirement.