Relevance. Currently, cabs with integrated rollover protection devices (roll over protective structure; ROPS) and protection against falling objects (falling-object protective structure; FOPS) are widely used for frontend loaders. If the design of FOPS is not affected by the mass parameters of the machine, then ROPS significantly depends on them. For a loader with ROPS, the cab is a difficult and expensive part. One of the ways to reduce the cost of its production is the unification of units for a standard-sized range of loaders. But then the ROPS design should be done for the loader model with the largest mass. However, this approach leads to an increase in the metal consumption and cost of loaders with a lower load capacity. As a result, the energy efficiency of the machine decreases.

A promising direction for improving energy efficiency is to reduce the weight of cabins through the use of aluminum alloys, because they have a high specific strength relative to steel. The objects of the study are wheeled front loaders with a gross weight of 10, 15 and 30 tons. The subject of the study is the application of computational methods based on the finite element method in the design of cabins made of aluminum alloys.

The purpose of the study is to develop a methodology for designing an aluminum alloy cabin frame, which will allow obtaining a cabin of lower weight and increased manufacturability compared to analogues.

Methodology and methods. The article presents the developed finite element models of structurally similar cabin samples in a static formulation, taking into account geometric and physical nonlinearities.

Results and scientific novelty. The paper presents a method for selecting the main design parameters of an aluminum alloy cabin.

Practical significance. The results obtained can be used to create cabs of front-end loaders.

The article is devoted to the review of the known designs of rotary-vane engines (RVE). The advantages of the RVE include high liter capacity, the absence of a gas distribution mechanism, ease of implementation of workflow management and potentially high efficiency.

Based on the results of the analysis of the structures, insurmountable shortcomings were identified that did not allow the use of RVE in practice.

The systematization of RVE design schemes based on the principle of converting the uneven motion of the rotors into a uniform rotation of the output shaft is proposed. According to this principle, three groups have been identified: a group of harmonic-sinusoidal circuits; a group of extreme-sinusoidal circuits and a group of synchronization circuits with stopped rotors.

It is established that a promising direction for improving the design schemes of RVE is a scheme with stopable rotors. This scheme theoretically provides the most efficient conversion of the pressure forces on the rotor blades into the torque on the output shaft of the engine.

The article presents the results of a theoretical analysis of the possibilities of approximation of real thermodynamic cycles to the reversible Carnot cycle. Typical examples are considered: regenerative cycle, Uvarov cycle and steam-gas cycle. The areas of application of "carnotization" of cycles are shown. The article is intended for teachers and students of technical universities.

The article briefly provides basic information about the principle of operation, design schemes and thermodynamic cycles of the Stirling engine. Advantages and disadvantages are considered. The predominant areas of application are shown. The article is useful for teachers and students of technical universities.

The article is devoted to the biography of the outstanding scientist, military engineer and teacher Stepanov Georgy Yuryevich - retired colonel, Doctor of Physico-Mathematical Sciences, Honored Worker of Science and Technology of the RSFSR, honorary Professor of the Military Academy of Armored Forces named after Marshal of the Soviet Union R.Y. Malinovsky, full member of the International Astronautical Academy, honorary member of the Russian Academy of Natural Sciences, member of the Presidium The National Committee for Theoretical and Applied Mechanics of the Russian Academy of Sciences.

The life path of Stepanov G.Yu. is a landmark of selfless service to the Fatherland, an example of true patriotism, dedication to the cause. The country should be proud of people like him, and people should know about them.