Расчет радиального смещения осей гайки и роликов и положения точки контакта резьбы гайки и ролика в планетарном ролико-винтовом механизме, выполненном по «Перевернутой» схеме

Inverted planetary roller screw mechanisms (PRSM) are used in a variety of drives in machine-building, aircraft, oil and gas industries, etc. Currently, such mechanisms are widely used in manufacturing the so-called electric cylinders. The difference of lead angles of the rollers and the nut causes radial misalignment of rollers axes, which results in mechanism preload. The preload affects the mechanism accuracy and efficiency and, in some cases, prevents its assembly. It is obvious that the value of the radial displacement of the axes of rollers relative to the axis of a nut should be taken into account to obtain a required mechanism preload and efficiency. This paper presents analytical relationships for calculating the position of initial contact points of accurate nut and roller threads, as well as an increase in axial distance between rollers and nut axes caused by the difference of their lead angles. Accounting for changes in axial distance makes it possible to design efficient mechanisms and estimate the magnitude of the preload required to run the mechanism and ensure its best efficiency.