Tribological Behaviors and Meshing Efficiency of a Novel Planar Ball Reducer Based on the Elastohydrodynamic Lubrication Theory

A novel planar ball reducer (NPBR) is invented in which the relative velocity of meshing surfaces is reduced to achieve high mechanical efficiency. In order to acquire an accurate quantitative analysis on the efficiency of a ball reducer, thorough comprehension of the reducer's tribological behavior is required. To this end, the elastohydrodynamic lubrication (EHL) theory, for the first time, is used to reveal the tribological behavior of the planer ball reducer, and the equations of kinematics, EHL model, and theoretical efficiency of the transmission system are derived. The prototype of NPBR is developed, and its experimental efficiency is measured, which agrees well with the theoretical efficiency.