Load Capacity of Spherical Roller Transmission with Double-Row Pinion

Abstract

Abstract This paper provides an in-depth description of the design and operating principle of a spherical roller transmission producing a wide range of reduction ratios in small dimensions. The rotational motion is transmitted from the drive shaft to the driven shaft by a pinion with two coaxial rows of rollers. The pinion performs a spherical motion about a fixed point on the transmission axis with a constant nutation angle. The rollers are in contact with a fixed periodic closed groove formed by two cams mounted in the housing and a groove made on the cam of the driven shaft. Power is transmitted through a number of parallel flows, which increases the load capacity, i.e., the maximum torque in the driven shaft. The main criterion of reliability is the contact strength of the cam surfaces. Equations for calculating contact stress in the roller-groove contact on the cam of the driven shaft are obtained by use of the Hertz theory. A formula for calculating the maximum torque being transmitted, which is obtained from the kinetostatic equilibrium equations, is given. The analysis of the influence of the main geometric parameters of the transmission on its load capacity is presented.