The design features of shredders and the type of feedstock have a decisive influence on the quality of the finished product and on the leveling of its granulometric composition. Inadequate quality of prepared feed reduces the effectiveness of using forage grains up to 30 %. For various species and age categories of animals and poultry, it is necessary to produce mixed fodders, nutritionally balanced and various in particle size. This article presents a methodology for assessing the efficiency of the process of grinding grain materials based on the actual performance of technological processes. The possibility of evaluating this indicator is achieved due to the differentiation of the mass of the finished crushed product into three fractions: the required size, non-hammer and grind, and the last two of them are substandard, requiring further impact on them. The proposed theoretical model characterizes this process from the qualitative aspect of its implementation. On the example of grinding characteristics of grain crusher "Zubrenok" it is shown how the technological process of grain grinding is estimated in accordance with the proposed method and allowed to detect about 28 % of the substandard fraction in the finished product, when its grinding module M = 2.1 mm corresponds to the zootechnical requirements of 1.8-2.6 mm. For comparison, the process of grinding grain in the hammer and rotor crushers and the correspondence of the State Standard product obtained in them are considered. Unlike the standard methods of evaluation by the grinding module and the degree of grinding, the actual effectiveness is more sensitive to changes in the granulometric composition of the finished crushed product.

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In order to ensure the best digestibility of feed, all the nutrients included in their composition should be given to animals in crushed form. Particle size of feed is different for all species and age categories of animals. The most common “shock” crushers give up to 30% of the dust fraction and up to 20% of the underground one. Nowadays, impact and centrifugal-rotor grain crushers that use a “slice-chipping” are the most effective ones. The small-sized horizontal impact crusher, which constructive and technological scheme of grinding is fixed in the patents of the Russian Federation, was made for carrying out experiments. The quality of the grinding process was assessed by three different indicators (the degree of grinding, the grinding module and the actual effectiveness of the process). Data on joint and separate grinding of wheat, barley, oats and corn were obtained. The conducted multifactorial experiment showed that the proposed design of the impact crusher allows obtaining up to 98% of the finished product balanced by the particle size at specific energy costs up to 2 WH/kg and productivity up to 260 kg/h. The most rational design and operating parameters of the horizontal impact crusher for various types of grinding were established on the basis of existing standards, zootechnical requirements and the latest scientific research. The developed horizontal impact crusher can be used instead of the widely used small-sized hammer mills, since, in comparison with them, its specific energy consumption is reduced to 50%.

Abstract. Renouncement and downtime of combine harvesters in operation lead to significant financial losses. One of the most important reasons for the downtime of this machinery is the failure of key connections, which account for up to 10.5 % of the total number of failures. The main disadvantage of this connection is that the keyway is a stress concentrator that reduces the fatigue strength of the parts, leading to an asymmetric deformation of the shaft and hub. The wear of individual parts of the fixed key connection is mainly due to the gradual surface destruction of the material of the parts, which is accompanied by the separation of particles, by changing the dimensions, geometric shape and properties of the surface layers of the material. The presence of gaps in the "bushing-shaft" connection also affects the reliability of the belt drives, since their constant pulsating loads, unloading and changing the inter-axis distance with variable frequency due to the turns of the key with the hub, take place. For real operating conditions of combine harvesters, the most effective installation is instead of existing key connections, where technical requirements permit, a removable hub for mounting a rotating element on the drive shaft, which can be made in the form of a repair kit with sufficient accuracy in the repair shops of farms. The use of the proposed modernized design of movable key connections first of all eliminates the main cause of the failure -the relative radial movement of the contacting mating parts, and also allows the hub and shaft to be pulled together without creating an eccentricity, which in turn will increase the service life of the connections. The article presents a method for calculating the transmission torque upgraded fixed connection, proposed for use in drives of combine harvesters instead of standard key connection. It presents the forces and tightening the conditions of the proposed strength of the connection.Keywords: combine harvester, resource, conical sleeve, torque, fixed connection. IntroductionIt is based on previous studies [1] that the refusal key connection harvester is a loss of efficiency of the whole machine. Therefore, in order not to disrupt the process of harvesting of grain crops, necessary measures have to be taken to reduce the cost recovery time performance of critical parts and components of the combine and increase their resources, including the key connection.Professor A.I. Yakushev [2; 3] proposed to use the factor of accuracy, which is the ratio of functional and design tolerances, to determine the accuracy of the geometrical parameters of the connection. Moreover, the accuracy stock should be created for each functional parameter affecting the performance of the product. According to the scientist, choosing the landing with the greatest accuracy factor of safety the durability of mobile connections increases, as the stock of materials for wear and the operational tolerance of landing increases.I.V. Kragelsky developed a frictional fatigue wear model that de...