Search results

The proposed scientific work considers and substantiates a new approach to selection of rational values of basic geometrical parameters of interference fit at their automated design – a fitting diameter and working length. A geometric and analytical model of the area was constructed, in which there are values of the basic parameters of fit. Then, numerical and analytical researches of this model were carried out. Based on the results of this research, an analytical criterion for choosing rational values of geometric parameters is formulated. The proposed method is based on the definition of the center of intersection of the largest segments of the permissible ranges of changes in the values of diameter and working length. This center is represented as some coordinate point within the model in the two-dimensional coordinate system. The coordinate axes of this model use the fitting diameter and the fitting length. The position of this point is analytically described using the mathematical apparatus of the theory of R -functions. These parameters are used in the automated design of the interference fits on the smooth cylindrical surface for jointed components of the direct engagement mechanical gears, for example, for the bandage joint of the ring gear to the wheel hub. This does have a keyless joint, the torque is fully transmitted by the friction forces in the fit. Such joints are used in the units and mechanisms used in small arms and artillery and military equipment, as well as other technical products of general-engineering purpose at various methods of assembly by a method of full interchangeability. The effectiveness of the method is shown in a specific example of numerical calculation, the results of which are obtained using the software developed by the team of authors of this work ; Пропонується новий підхід до вибору раціональних значень геометричних параметрів посадки з натягом на базі їх аналізу у автоматизованому проектуванні досліджуваного з'єднання за сформульованим у статті аналітичним критерієм пошуку значень посадкових довжини і діаметра. Ефективність методу показана на конкретному прикладі чисельного розрахунку.

The proposed scientific work considers and substantiates a new approach to selection of rational values of basic geometrical parameters of interference fit at their automated design – a fitting diameter and working length. A geometric and analytical model of the area was constructed, in which there are values of the basic parameters of fit. Then, numerical and analytical researches of this model were carried out. Based on the results of this research, an analytical criterion for choosing rational values of geometric parameters is formulated. The proposed method is based on the definition of the center of intersection of the largest segments of the permissible ranges of changes in the values of diameter and working length. This center is represented as some coordinate point within the model in the two-dimensional coordinate system. The coordinate axes of this model use the fitting diameter and the fitting length. The position of this point is analytically described using the mathematical apparatus of the theory of R -functions. These parameters are used in the automated design of the interference fits on the smooth cylindrical surface for jointed components of the direct engagement mechanical gears, for example, for the bandage joint of the ring gear to the wheel hub. This does have a keyless joint, the torque is fully transmitted by the friction forces in the fit. Such joints are used in the units and mechanisms used in small arms and artillery and military equipment, as well as other technical products of general-engineering purpose at various methods of assembly by a method of full interchangeability. The effectiveness of the method is shown in a specific example of numerical calculation, the results of which are obtained using the software developed by the team of authors of this work ; Пропонується новий підхід до вибору раціональних значень геометричних параметрів посадки з натягом на базі їх аналізу у автоматизованому проектуванні досліджуваного з'єднання за сформульованим у статті аналітичним критерієм пошуку значень посадкових довжини і діаметра. Ефективність методу показана на конкретному прикладі чисельного розрахунку.

The article examines the urgent problem concerning possible destruction of a partly liquid-filled skinned capacity within the temperature field as a result of firmness loss on verge of filling level.Skinned constructions used as capacities for storing and transporting highly dangerous liquids (Level 3 of danger), such as: oil products, nitrates, alkali, low-boiling substances are often within the temperature field, and possible destruction caused by their running-out might result in catastrophic effects. Therefore, to prevent such effects, one should have good understanding of the above mentioned phenomenon as well as recommendations as for safety maintenance of these capacities. Taking into consideration the complexity of calculation chart and mathematical model of this task, the authors applied the integral transformation of Fourier to solve the task that made it possible not only to simplify the decision but to get the result in the form of exclusive formula.The analysis of the formula proves that the level of critical temperature greater depends on the ratio of radius to thickness with wide range of changes than on the coefficient of linear expansion that is close by its dimensions to basic metallic constructions. This formula and its graphic presentation make it possible in the mode of express-analysis to define durability of a partly liquid-filled skinned capacity within the temperature field that is extremely important both in the national economy and in the military sphere. ; Розглядається нагальна проблема руйнування частково заповненої рідиною оболонкової ємності при її нагріванні внаслідок втрати локальної (місцевої) стійкості під дією перепаду температури на межі рівня заповнення.

The article examines the urgent problem concerning possible destruction of a partly liquid-filled skinned capacity within the temperature field as a result of firmness loss on verge of filling level.Skinned constructions used as capacities for storing and transporting highly dangerous liquids (Level 3 of danger), such as: oil products, nitrates, alkali, low-boiling substances are often within the temperature field, and possible destruction caused by their running-out might result in catastrophic effects. Therefore, to prevent such effects, one should have good understanding of the above mentioned phenomenon as well as recommendations as for safety maintenance of these capacities. Taking into consideration the complexity of calculation chart and mathematical model of this task, the authors applied the integral transformation of Fourier to solve the task that made it possible not only to simplify the decision but to get the result in the form of exclusive formula.The analysis of the formula proves that the level of critical temperature greater depends on the ratio of radius to thickness with wide range of changes than on the coefficient of linear expansion that is close by its dimensions to basic metallic constructions. This formula and its graphic presentation make it possible in the mode of express-analysis to define durability of a partly liquid-filled skinned capacity within the temperature field that is extremely important both in the national economy and in the military sphere. ; Розглядається нагальна проблема руйнування частково заповненої рідиною оболонкової ємності при її нагріванні внаслідок втрати локальної (місцевої) стійкості під дією перепаду температури на межі рівня заповнення.