Fodder production is one of the most important sectors of the agro-industrial complex of Ukraine, the pace and scientific and technical level of development of which largely determines the solution of the country's food problem, full satisfaction of the population's food needs. A limiting factor for the development of this industry is the lack of efficient, easy-to-use and cheap equipment for collecting, raking, stirring, and pressing domestically produced hay, which would be able to compete with foreign analogues. The publication is devoted to the development of a hydraulic drive of the working bodies of the rake of a thief. The analysis of the designs of the existing machines for raking hay into rolls is carried out. A characteristic feature of these machines is the presence of specialized working bodies and the need to ensure a given frequency of their rotation. The proposed hydraulic scheme for the drive of the working bodies. The hydraulic drive consists of a variable displacement pumping station, a hydraulic flow divider and two hydraulic motors. The use of this drive allows to simplify the layout of the machine and provide an efficient drive in compliance with all process requirements. In addition, the use of a hydraulic drive allows you to increase the number of working bodies, thereby increasing the width of the rake - hackers. The introduction of these changes in the design of this unit will allow to reduce the number of passes of the rake-hacker and pick-up press across the field, thereby ensuring fuel economy. As the review of literary sources shows, the issues of collecting and storing hay are relevant not only for our country, but also for other European countries. The designs of domestic rakes - hackers are morally obsolete, do not meet modern agrotechnical requirements, have a small working width and require frequent repair and maintenance. Based on the results of the analysis of the designs of the drives of the working bodies of the rake - hackers, a hydraulic scheme for the drive of the working bodies was proposed. A feature of this hydraulic drive is the presence of a throttle flow distributor with the possibility of smooth flow control.

Intensive use of agricultural production technologies has recognized the intensive characteristics of agricultural producers, which allowed to present the need for frequent diagnostics, maintenance and repair. This transition is due to objective trends in the development of agricultural machinery. The solution to this problem involves the development and creation of effective tools for monitoring and diagnosing the state of the transmission elements of agricultural machinery; assessment of the value of the residual life of individual elements of the system and the study of energy conversion processes in these elements; construction of mathematical models on the basis of which it is possible to predict the occurrence of dangerous damage depending on the operating conditions of the equipment. Diagnostic means must ensure the assessment of the condition of the working surfaces of the interacting transmission elements, control of wear of their surfaces and assessment of the performance of the unit as a whole or the kinematic pair without their disassembly during operation. The time of collection of diagnostic information and allocation of informative signs and parameters of signals should be minimized. Control methods should be as simple as possible, and the means that implement them - compact, with built-in algorithms for information processing and decision-making. The most informative parameter that carries the maximum information about the state of the unit of a working machine or unit is mechanical oscillations (vibrations) - elastic waves propagating in continuous media. Measurement of vibroacoustic characteristics on bearing supports of mechanisms allows to recognize such defects and damages as imbalance and skew of shafts; damage to plain and rolling bearings; damage to gears in gears; damage to couplings; damage to electrical machines. With the systematic use of modern diagnostic methods it is possible to avoid serious damage to the transmission elements and reduce operating costs for maintenance of agricultural machinery due to the fact that the repair is carried out only when the measurement results indicate its need.