Peculiarities of the Development and Manufacturing of the Prototype of Gapless Planetary Roller Screw Mechanism

Abstract

Known designs of gapless planetary roller screw mechanisms (PRSM) are highly accurate and rigid, but have low load capacity and short life. To eliminate these shortcomings, a new design of a gapless PRSM was developed and patented using a one-piece thin-walled nut. Due to radial deformation of the nut, the gaps between the threaded parts of the mechanism are chosen. The previous works have described the design of a new gapless PRSM and theoretically proved the possibility of a significant increase in load capacity and life using this mechanism. To confirm the theoretical results and conclusions, it is necessary to conduct experimental studies for which a prototype of the new gapless PRSM was made. The work presented describes a new technology for manufacturing threaded parts of this mechanism. In contrast to the traditional technology of grinding screw surfaces of the PRSM parts, which require special expensive equipment, it is proposed to grind and bore the screw surfaces of the parts with special plates on CNC turning machines. The metrological control has established that the dimensions of all parts of the prototype, including the threaded parts, did not go beyond the fields of the calculated or assigned tolerances.