GEOMETRIC ANALYSIS AND THEORETICAL EFFICIENCY EVALUATION OF THE CONE-AND-PLATE ENGAGEMENT OF A SPHERICAL ROLLING SCREW MOTION DRIVE

Abstract

The study objective was to assess the influence of friction factors and geometric parameters of a spherical rolling screw motion drive on its efficiency. The load is transferred by means of a cone-and-plate engagement of two rows of rollers mounted on a satellite with fixed and driven plate central gears. With the help of a spherical rolling screw motion drive, it is possible to realize a wide range of gear ratios (16...200) and reduce the material capacity of the gearbox, ensuring the ratio of its mass to the nominal transmitted torque of less than 0.1 kg/(N•m). The main task of this research is to find out the ascent angle of the spatial closed center curves with the help of which the surfaces of the central wheel teeth are formed. The research methods are based on the application of the classical mechanics laws and computer modeling algorithms in NX system. The novelty of the research is in the novelty of the technical object under study, its low level of being studied, the lack of detailed methods of its calculation and design. As a result, based on the analysis of the geometric satellite model, the equations of the center curves are obtained and an algorithm for determining the ascent angle of the center curve in the middle section of the central wheel teeth is developed, which allows power analysis of the motion drive. The applicability of the formula for calculating the average ascent angle of a piecewise helical curve located on a cylindrical surface for spherical motion drives is evaluated and the necessity of its adjustment taking into account a given gear ratio and the inclination angle of the drive shaft crank is found out. An algorithm is developed for the theoretical study of the efficiency of spherical roller gears at the design stage.