| Summary: | It is established that at the present moment the roller screws (RS) are the most challenging mechanical transducers of rotational motion into forward motion. For that reason their field of application is being constantly enlarged. In the West one can observe the tendency of the replacement of hydraulic drive by RS-based electromechanical drive. The main RS parts are screw, thread rollers and female screw which on the load transmission interact in the contact lands located on the pitch diameters of the special thread of these parts. To exclude the edge contacts on the male screw and female screw the thread with triangular profile waps are performed, on the rollers – with convex profile. Besides the pitch diameters of the male screw, rollers and female screw thread form the closed-loop dimension chain, and the values of these diameters affect the RS axial play and its performance capabilities significantly. Therefrom in manufacturing thread pieces it is required to carry out the high-precision control of their thread pitch diameters. For the male thread this control is carried out by means of three cylindrical wires with preferred diameter. Such wires are available at the factories of the Russian Federation and are represented in AllUnion State Standard 2475-88 for the standard thread (metric, trapeziform and others), and they are not available for the RS pieces special thread. It was proposed for the RS pieces male thread pitch diameter control to use the standard wires, the diameter of which is the next larger to the necessary preferred diameter of the RS piece controlled thread. The article presents the preferred diameters of the wires for the RS thread pieces control with employed pitch of the special thread. The dependencies for sizing up of the RS pieces male screw and roller pitch diameter dimension control is deduced by utilizing the wires of unspecified diameter, including preferred diameter. In view of the RS potential it is required to set up in Russia the production of wires with preferred diameters for the RS pieces male thread control. In the long term while reexamination of the All-Union state standard 2475-88 it is required to enlarge the range of smooth wires with new ones intended for RS advanced concepts pieces male thread pitch diameter control.
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