The determination of technological error in spherical 4-link hinged mechanism

Abstract

THE DEVELOPMENT of science and technology is closely connected with the creation of new, modern, high precision mechanisms and machines and with the creation of sensitive devices producing parameters of motion with high accuracy. Mechanisms are applied widely in measuring devices, in computing devices, in recording and registration equipment, in Optical instruments, in distance-controlling devices and others. As is known, in real mechanisms the actual dimensions may be different from the theoretical. The difference wil! be caused by the inaccuracy of mechanism assembly and by the clearances in the bearings of kinematic pairs providing relative displacements of links. In addition the effective forces on the links may cause the deformation of the links. Deformation may also be caused by an alteration of temperature or other effects. Determination of error in the position of a mechanism, when all factors causing the error (technological, installation, temperature, deformation, influence of bearing clearance, position of the driving link, and others) are considered, is expressed by highly complex interrelations. In most cases, the common error A in the performance of a mechanism on the whole may be expressed by a functional dependence of the following form