The Influence of Thermal Stresses on the Load Distribution in Cycloidal Reducers

Abstract

High precision reducers (HPRs) are being increasingly used in modern industrial systems, especially in industrial robots. That is why the number of installed cycloidal reducers (the most commonly used HPRs) is increasing year after year. In order to design a cycloidal reducer, to determine its efficiency and distribution of stresses and deformations, it is necessary to know the intensity and character of the load. A number of papers dealing with this subject have been published. They analyse the influence of different parameters on the load distribution in cycloidal reducers, such as clearances, modification of the cycloidal disc tooth profile, etc. This paper analyses the influence of thermal stresses (which occur during operation) on distribution of contact forces between the central rollers and the cycloidal disc teeth. This analysis is very important because high operating temperatures affect the size of clearances between the elements that transfer the load and, thus, the number of elements in contact. Intensities of thermal sources were determined analytically (Matlab), while the contact forces were determined numerically using the Ansys software. The obtained results showthat the influence of temperature on distribution of contact forces cannot be ignored, especially with frequent starts, stops and considerable overloads.