Dimensional Joint Running-in of Cylindrical Parts of Mining Machinery

Abstract

The current task of engineering is to ensure the quality and reliability of critical parts of an extended cylindrical shape. This task is especially relevant in the production of power hydraulics parts for mining equipment (ME). One of the ways to ensure the required quality of the surface layer (SL) of mining equipment parts is the use of combined and joint methods of parts hardening by surface plastic deformation (SPD). Combined methods present sequential machining in which the methods used are separated into different technological steps, while the joint machining is carried out by concentrating the methods into one technological step (setup). The analysis shows that this approach, although it has a number of indisputable advantages, allowing an increase in the accuracy, machining efficiency and SL quality, is not without drawbacks that hinder the use of combined and joint machining methods in the manufacture of parts with IT 8-9 accuracy. The dimensional joint running- in method (DJR) is based on the original scheme of interaction between the cutting and deforming tools allowing a cylindrical surface with an accuracy of IT 8-9 and a roughness of no more than Ra 0.4 μm, hardened to a depth of 10 mm in one pass. The study shows the possibilities of a much greater SL deformation without its destruction than with the traditional SPD. The analysis of the structure and basic technologies has shown the feasibility of replacing a number of turning and grinding operations with one dimensional joint running-in operation. The design of the device for DJR based on a lathe is given. The completed economic calculations have established that it is possible to implement this method in the existing economic situation.