A significant proportion of the costs and downtime for repairs are on transmission units, and especially on the gearbox (GB). Based on the research results presented in the work, up to 76% of all transmission failures fall on the gearbox of a KamAZ 6540 automobile under ordinary operating conditions. The purpose of the study is to justify the repair and maintenance cycle (RMC) of the gearbox of the KamAZ 6540 automobile, taking into account the pre-repair operating time. The proposed methodology for assessing the pre-repair resource allows you to select the resource elements of the gearbox, taking into account the value of their resource and coefficient of variation. The structure of the RMC proposed in the work provides for: the first current repair during running hours - 125940 km; first overhaul during running hours - 251880 km; second current repair during running hours - 377820 km; second overhaul during running hours - 503760 km. Thus, changing the structure of the gearbox REC allows increasing the gearbox resource from 380 to 500 thousand km.

In this paper, we consider the use of the polarization-optical method for assessing the stress-strain state of films of polymeric material in the restored tribomechanical system “bearing ring - housing” and the dependences for determining the magnitude of the principal stresses are proposed. When studying the stress-strain state, compounds with a diameter of the contact surface of 40 mm from an optically sensitive material imitating an adhesive layer were used as models. The photoelasticity method showed that the maximum stresses occurred on the axis of symmetry of the model, and the contact arc was 180 degrees. A qualitative picture of the strips indicates the identity of the stress-strain state of the adhesive joint model both for the uniform gap model and for the eccentricity models.

The failure-free performance of the components determines the technical and economic efficiency of the use of the combine harvester. A low level of reliability leads to an increase in the cost of harvesting, the need for unscheduled repairs due to failures of parts, assemblies and assembly units. Studies have shown that a significant proportion of failures occur in power transmission units. In this regard, the aim of the work is to assess the reliability of the power transmission of the John Deere 9660 combine harvester. The average time between failures of the power transmission units was 80 hours, which does not meet the regulatory requirements (according to STO AIST 8.22 - 2010 - at least 100 hours). Failures of all powertrain assemblies are caused by a combination of failures: wear and fatigue failure of the bore holes for the bearings of the unit housings, and gears, bearings from dynamic loads.

Basic oils produced from oil or obtained by the synthesis of monomers are generally chemically neutral. To improve the service properties of base motor oils, additive packages and active ingredients are introduced into it. The presence of anti-seize, anti-wear, and dispersing-stabilizing additives in a composition of commercial oil of a certain concentration of compounds of alkali metal salts changes its chemical activity [1]. Based on this, as a measure of service properties (anti-seize, anti-wear and dispersion-stabilizing properties (DSP)) of commercial motor oils can be used hydrogen indicator - pH. In the work, as an invariant estimate of the concentration of resource additives and service properties of commercial motor oils, the use of pH is considered. Correlation dependences of pH on BSP and viscosity of the studied motor oil are given.

A decrease in the technical potential of the agro-industrial complex of the regions and Russia due to a decrease in the availability of equipment and significant aging is shown, which imposes special requirements for ensuring its performance due to a well-organized technical service. It is possible to maintain high availability of machinery through the regional system for ensuring the operability of agricultural machinery. The aim of the study is to develop a method for ensuring the operability and availability of equipment for its effective use based on the use of service technical clusters. The system for ensuring the operability of agricultural machinery provides various options for servicing consumers from the following levels: economy, district and region. A normative and calculation method is proposed for determining the parameters of the regional system for ensuring the operability of agricultural machinery in order to reduce labor intensity, according to which its parameters are calculated for model technical service clusters: economy and district. The obtained parameters for model levels of the economy and the district are adjusted taking into account the main actual indicators for the zone served by this level of the system. The proposed regulatory calculation method for determining the parameters of the system for ensuring the operability of agricultural machinery was implemented for the Novosibirsk region. Based on a certain laboriousness of the equipment being serviced, a regional model service cluster and a model service cluster of a farm (a farm with average indicators for the region) are substantiated. The conversion factors from model service clusters to actual enterprises at the district and farm levels are given.