Improvement of roller assemblies designs of pellet and roasting carriages

Abstract

The article analyzes the known designs of roller carriages used to manufacture sinter and pellets on conveyor lines. The authors analyze the design features of running and load rollers, the use of roller and ball bearings to connect rollers to the axles, various types of antifriction fillers of bearings, bearing lubrication system; blind, stuffing box and graphenite seals. The article points out the advantages and disadvantages of roller designs, the lack of standard technical solutions for the design of roller assemblies, as well as reliable methods for calculating their parts for strength and durability. To increase the service life of the rollers, after successful industrial tests, the authors propose innovative technical solutions: seals in the form of stuffing box packing made of expanded graphite fibers reinforced with steel thread; bearing antifriction filler made of PTFE, carbon fiber and graphite. The article shows that, due to axial loads during the operation of the carriages, it is impractical to use ball bearings in rollers; they should be replaced with roller bearings. The authors propose an approximate method for calculating the durability of bearings, which, unlike the existing standard methods, additionally takes into account the elastic deformation of the bogie material during thermal expansion and the size of the gaps in the assemblies of the carriages. In their calculations the authors use the experimental results on the size of the gaps in the assemblies of the carriages, the curvature of the body of the heated carriages on the conveyor line and their movement on three rollers instead of four; they take into account the change in the coefficient of linear expansion of the carriages material depending on the increase in the heating temperature of the body. The calculation results can serve as the lower limit for estimating the service life of ball bearings with antifriction filler