Analysis of contact strength of spherical roller transmission with double-row pinion

Abstract

This paper presents a detailed description of the design of the spherical roller transmission. The pinion has two rows of rollers; the axes of the rollers are located on conical surfaces. When the transmission is operating, the pinion performs a regular precession and the rollers are in contact with the teeth of the stationary and driven central gears. The transmission provides high reduction ratios in a lightweight, compact package. The center of mass of the pinion is located on the axis of rotation of the drive shaft, which reduces the axial moment of inertia and improves the balance of the system compared to double-pinion planetary gears mounted on the drive shaft with eccentricity. Rolling bodies are used in place of teeth, which leads to improved efficiency. The main performance criterion is the contact strength of the teeth of the driven central gear. An equation to calculate maximum contact stresses has been derived by using Hertz theory. An algorithm for calculating the number of the rollers simultaneously engaged and transferring the load is proposed.