Ukrainian Journal of Mechanical Engineering and Materials Science

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    Research on the characteristics of gear-cutting processes for external and internal meshing using the power skiving method
    (Видавництво Львівської політехніки, 2023-02-28) Hrytsay, Ihor; Slipchuk, Andrii; Bembenek, Michal; Lviv Polytechnic National University; AGH University of Krakow
    The results of modelling and investigation of external and internal gear-cutting processes using the power skiving method are presented. The principles of constructing a geometric model of undistorted chip formation are described, based on parameters from which cutting forces are calculated. It is found that, under identical conditions, the cutting force is three times greater when internal gears are cut than when external gears are cut. The influence of this force on the machining error is determined by the gear pitch parameter. It is shown that the most rational way to reduce the machining error is to reduce the cutting force by reducing the axial feed rather than by increasing the number of passes.
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    Experimental improvement of the technology of cutting of high-pressure hoses with metal braid on hand cutting machine
    (Publishing House of Lviv Polytechnic National University, 2016) Karpenko, Mykola; Bogdevicius, Marijonas; Prentkovskis, Olegas
    In the article the review of the problem of improvement of technology of high pressure hoses cutting on the hand cutting machines is analyzed. Different methods of cutting of high pressure hoses into the billets are overviewed and the quality of edge cuts of hoses is analyzed. The comparison of treatment on automatic cutting machines and on hand cutting machines is carried out. Different experimental techniques of improvement of the quality of edges cutting of high pressure hoses are presented. On the basis of experimental method, a new cutting technology which consists in maximally close fixation of high pressure hoses to the cutting disc is proposed. In the basic design of the hand cutting machine, the only supports are provided, so that the cutting of the edge section of high pressure hoses causes the metal braid loosening. The proposed technology excludes the scrolling and bending of high pressure hoses during cutting, so that the loosening of metal braid is also excluded. In the paper it is shown that the scheme of distribution of cutting forces during the cutting of high pressure hoses is presented and the mathematical model of determination of normal and tangential cutting forces is formed. With a help of tensiometric table the values of components of cutting forces during free and fixed cutting of high pressure hoses were defined and their comparison was performed. As a result of the use of this technology the edges of the cut off high pressure hoses meet the necessary requirements without using of complicated technological processes.