Validation of the Model of Elastoplastic Contact of Spiroid Gears

The paper considers the problem of analyzing the elastoplastic contact of teeth in a heavy-loaded low-speed multi-pair spiroid gear. This problem is an integral part of the strength analysis that enables forecasting the load-carrying capacity of the product at the initial stage of its development. The relevance of the considered method and algorithm of calculating the load distribution and plastic strain of teeth is emphasized by its increased productive efficiency as compared to the widely used finite element method. The paper considers a common issue of validation of the developed algorithm, i.e. the correspondence of the obtained solution to the results of a real loading process. The main steps of the algorithm are given with account of the multi-pair contact and macro-roughnesses on the contact flanks that are represented as the set of areas (cells). The coordinates of the cell centers are calculated taking account of the factors influencing the load distribution in the spiroid gearing, such as manufacturing and/or assembly errors, surface micro- and macro-roughnesses, and deformations of the gearbox parts. To validate the algorithm, only one dominating factor — the gearwheel surface undulation — is chosen, since all the other factors are negligibly small. The object of the study is a gear in one of the mass-produced multi-turn spiroid gearboxes for pipeline valves. The criteria for the algorithm validation are formulated, namely, the plastic strain value, the area, shape and arrangement of the pattern of the plastic strain. By analyzing the results of numerical and experimental modeling it is possible to draw a conclusion on the validity of the results obtained by means of the studied numerical method of analysis. The divergence of the plastic strain value obtained experimentally and through calculation was under 10%, and the area of the plastic strain pattern was under 10%.