РАССМОТРЕНИЕ УСТРОЙСТВ И СПОСОБОВ УПРОЧНЕНИЯ ГАЛТЕЛЕЙ ТЕЛ ВРАЩЕНИЯ ППД, ИХ КЛАССИФИКАЦИЯ И РАЗРАБОТКА РЕКОМЕНДАЦИЙ ПО СОВЕРШЕНСТВОВАНИЮ

Abstract

The service life of heavily loaded shafts is largely determined by the degree of stress in the transition area from one diameter to another. There are a fairly large number of methods for reducing the stress concentration of these areas, but a special place in this case is occupied by strengthening the surfaces of non-profile, heavily loaded shafts. First of all, their fillets are subjected to hardening, which leads to the formation of uniformly distributed compressive stresses in the technological zone and, accordingly, an increase in the fatigue strength of such parts. The method has become especially widespread when hardening crankshafts. Along with this, surface hardening is applied to the abovementioned part to eliminate its bending. This technological process is especially important in the case of restoration of rotating parts. Meanwhile, existing work in this area does not solve existing issues. In this regard, it is necessary to give a critical analysis of the methods and designs for PPD fillets with the development of appropriate proposals, which determines the relevance of the work. The purpose of the study is to consider devices and methods for strengthening fillets of bodies of rotation of PPD, their classification and development of recommendations for improvement. To reveal the goal, the authors conducted a comprehensive review of the information available in the public domain regarding the strengthening of fillets by cold hardening. This made it possible to identify their advantages and disadvantages. First of all, this is the lack of a unified classification system, as well as methods for preventing the formation of a “wave of deformation”. Based on the analysis, a classification is proposed based on the factors that determine the properties of the shafts and the quality of their surface layers and the functional purpose of the processing. A proprietary scheme for processing SPD surfaces is proposed, which ensures the prevention of a “wave of deformation” in one pass of the working tool, which is based on the well-known principles of the theory of the introduction of a ball indenter into a solid.