The influence of reduced voltage on the service life of an induction motor is considered in this article. An algorithm for calculating the rate of thermal wear of induction motor insulation under reduced supply voltage depending on the load and the mechanical characteristics of the working machine has been developed. It determines the change in the rate of thermal wear under alternating external effects on the motor (supply voltage and load) and allows forecasting its service life under these conditions. The dependency graphs of the rate of insulation thermal wear on the motor load for various levels of supply voltage and various mechanical characteristics of working machines are provided in the work. It was determined that the rate of thermal wear of the induction motor insulation increases significantly when the voltage is reduced compared to its nominal value with nominal load on the motor. The authors propose to consider this fact for resource-saving control of the motor. The paper presents the results of experimental verification of the obtained rule for “Asynchronous Interelectro” (AI) series electric motors that confirm its accuracy. Based on the obtained correlation, the rule of voltage regulation in energy-saving operation mode has been derived. The proposed rule takes into account the thermal impact on the electric motor running in energy-saving mode and enables saving its resource, which, in turn, results in extending its service life. The research does not consider additional effects on the electric motor except the thermal one.

The operation principles of both new and improved clamping mechanisms of the CNC lathe with the automatic no–reinstallation workpiece manipulation are described in this article. The theoretical analysis of power characteristics with the spindle in rotary and non-rotary modes has been carried out with the account of unbalanced chuck jaws’ centrifugal forces. The efficiency of the new clamping mechanism at a higher spindle velocity has been justified

Based on the analysis of standards for the testing of lubricants, both liquid and plastic, on a four-ball tribometer, and the analysis of the parameters by which lubricants are evaluated, this paper proposes a methodology and an integral parameter for the estimation of tribological properties. The methodological approach proposed in this paper allows for the integration of a variety of parameters provided in the standards for the testing of lubricants into one indicator. Herein, we show that the developed technique is based on the energy approach and takes into account the specific wear work of the test material (steel balls) in the lubricating medium to be investigated. The results of laboratory tests of a wide range of lubricants are presented: hydraulic fluids, motor and transmission oils of various purposes and classifications. It is shown that the magnitude of the integral parameter can be used to assess the effectiveness of anti-wear and anti-scuff additives in base lubricants, as well as the ranges of their applications. This allows for differentiation and quantitative evaluation of the effectiveness of such additives. The obtained results allow us to state that all tests according to the developed method are reproducible and homogeneous, which is confirmed using the Cochran criterion. The coefficient of variation during testing does not exceed 18%. We show that the presented methodology and the integral parameter can be used in the first stage of the laboratory selection tests of new lubricants and additives of various origins, reducing the costs of their development and implementation.

Self-organization mechanisms of metastable dissipative structures during friction depending on base and oil functional additives for hypoid gears are considered. Research was conducted on a software-hardware complex with simulation of gears operation in rolling with slipping conditions in start-stop mode. Indicators of formation of wear-resistant dissipative structures include the following: improvement of antifriction characteristics, lubricant boundary layers formation, contact surfaces strengthening, and formation of heterogeneous deformation microrelief with a fine-grained structure. The formation of chemically modified boundary layers on 90 of the contact area of tribo-coupling elements ensures an increase in the wear resistance of leading and lagging surfaces by 2 and 1.4 times, respectively. The sclerometry method was used to establish that the formation of dissipative structures when lubricating tribo-coupling elements with various transmission oils can reduce deformation processes in metal near-surface layers by 23. Highly viscous flavored lubricant with distillate oil and additive composition ensures wear-resistant dissipative structures with active components, including oxygen, sulfur, and phosphorus.

The regularities of the wear of the steel 1045 during cutting off the feed of a lubricant under the non–stationary friction conditions were established. The influence of the properties of the secondary structures, formed on the contact surfaces under conditions of rolling with a different degree of slippage, on the wear of advancing and lagging surfaces was determined. The influence of specific friction work, the degree of hardening – weakening of surface layers of metal and the intensity of saturation by active elements of near–surface layers of metal on the wear resistance of friction pairs is examined. The change is established in localization of the depth of spreading the stressed and deformed state of material of the contact surfaces with an increase in the slip rate from 0.315 m/s to 1.14 m/s at rolling with the slippage.

In the presented work, a methodical approach was developed for determining rational operation modes of tribosystems, taking into account their design. This approach makes it possible in the designing stage, according to the predicted operating modes, to calculate the limits and margins of stable work in operation. The definition of the robustness of the tribosystem and the criteria for assessing the robustness are formulated based on the theory of stability of technical systems. It is shown that such a methodical approach allows for determining the modes of the rational operation of the designed structures without damaging the friction surfaces. Experimental studies have proven that not all designs of tribosystems lose stability due to the appearance of friction surface burrs. There are designs where the loss of stability occurs upon the appearance of accelerated wear. The developed criteria take into account two options for the loss of stability. An experimental verification of the modes of loss of stability of tribosystems was performed by the appearance of a burr or the beginning of accelerated wear with the calculated values of the robustness criteria. The obtained results allow us to conclude that the modeling error is within 8.3–18.7%, which is a satisfactory result in the study of friction and wear processes. Robustness criteria is based on the coefficient of friction RR_f and wear rate RR_I, and must be used when designing new constructions of tribosystems. Theoretical calculations of such criteria and the dependence of their change on changing the predicted operating modes will allow for justifying rational operating modes within their stability.