V . R u t k e v y c hPhD* E-mail: v_rut@ukr.net S . S h a r g o r o d s k yPhD, Associate Professor* E-mail: serganatsharg@gmail.com *Department of Machinery and equipment for agricultural production Vinnytsia National Agrarian University Soniachna str., 3, Vinnytsia, Ukraine, 21008Досліджено та змодельовано процес видавлю вання різі з накладанням ультразвукових коли вань. На основі реологічної моделі деформування ідеального пружнопластичного тіла розробле ні залежності для розрахунку контактних тис ків та питомої сили тертя. Змодельовані кон тактні явища, що проходять в зоні деформації. Визначені оптимальні параметри видавлювання різі. Аналітично визначено діаметр отвору під видавлювання різі з накладанням ультразвуко вих коливань Ключові слова: ультразвукове видавлюван ня різі, частота коливань, амплітуда коливань, контактний тиск Исследован и смоделирован процесс выдавли вания резьбы с наложением ультразвуковых коле баний. На основе реологической модели деформи рования идеального упругопластического тела выведены зависимости для расчета контактных давлений и удельной силы трения. Смоделированы контактные явления, которые проходят в зоне деформации. Определены оптимальные парамет ры выдавливания резьбы. Аналитически опреде лен диаметр отверстия под выдавливание резьбы с наложением ультразвуковых колебаний Ключевые слова: ультразвуковое выдавлива ния резьбы, частота колебаний, амплитуда коле баний, контактное давление UDC 621.9.048.6

The paper considers the problem of reducing the drive power of the mechanism for separating stalk feed from trench storages by the batch method by developing and substantiating the parameters and operating modes of the hydraulic drive system. The structure and principle of construction of a system of hydraulic drives of the mechanism for separating a portion of stem feed are proposed. This will significantly reduce the power of the used hydraulic motors by simultaneously controlling the cutting speed of the monolith of stem feed and the feed of the cutting device. The analysis of changes in the physical and mechanical properties of stalk forage (silage and haylage), depending on the height of occurrence in the trench storage, has been carried out. The process of separation of the stalk feed from the feed monolith is considered. The complexity of the technological process of separating the portion of the stalk feed from the feed monolith due to the change in the physical and mechanical properties of the feed from the height in the trench storage and the lack of adaptation of the loader drive to such differences is indicated. A basic hydraulic diagram of the loader drives is proposed, which is based on the dependence of the cutting force of the material on the parameters of cutting modes. The theoretical foundations of the calculation were formulated by I. Timme and later adapted to the peculiarities of the work of agricultural machinery by V.P. Garyachkin. This theory allows you to determine the cutting force on the working body of the cutter bar depending on the cutting speed, feed of the cutter bar and depth of cut. An adaptive hydraulic drive of the mechanism for separating the stalk feed is proposed, which makes it possible to coordinate the operation of the cutter bar drive with its supply. The possibility of reducing the drive power of the mechanism for separating the stalk feed to 5-6 kW when using a system of hydraulic drives with a mechanism for adapting the working bodies to their working conditions has been confirmed. The modes of operation and the possibilities of increasing energy efficiency, competitiveness of technological machines and aggregates of the agro-industrial complex, by developing and substantiating the parameters of the hydraulic drive system, are indicated.

The paper reviews the state of research of wave processes in hydraulic systems of machines, and their impact on the quality and stability of hydraulic drives. As noted in the works of previous researchers, these phenomena occur in hydraulic systems and adversely affect the quality and stability of their work, significantly reducing reliability. The method of construction of mathematical models is offered. A mathematical model of the hydraulic system with two series-connected hydraulic motors is built, taking into account transients. The Runge-Kutta-Feldberg method with automatic change of the integration step was used to solve this model. The application of this method makes it possible to estimate the amplitude and frequency of the pressure wave in real time for each part of the pipeline. As a result of the analysis of the obtained transients it was concluded that at the length of the pressure line in a group hydraulic drive with 2 series-connected hydraulic motors up to 1.5 m, wave processes do not significantly affect the system and in the mathematical model they can be ignored. With the length of the pressure line from 1.5 m to 9 m, the wave processes in the cavity do not affect the stability of the system, although significantly impair the quality of its work. Hydraulic systems with a pressure line length of more than 9 m are not recommended for implementation, because the wave processes in the cavity lead to vibrations and noise in the hydraulic system and require additional measures to eliminate the impact of this phenomenon.

The paper presents the calculation results of the two mathematical models of the variable displacement axial piston pumps PVC 1.85. In the first mathematical model of the pistons averaged force was used, the application point of which corresponds to the offset of the swash plate’s swivel axis. In the second mathematical model the parametric change of the pistons consolidated force magnitude and the coordinates of its application point was taken into account.

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