This article is about motorless studies of crankshaft dampers of combustion engines. An option to reduce the adverse effect of torsional motions of the crankshaft to the working life and effective performance of the engine is the dampers’ installation. However, dampers’ installation causes a change in the number of motor masses, what in turn results in a change in free frequency. As a consequence, there are changes in the resonant modes of operation, and ones in the type and shape of the constrained oscillations. To ensure the efficient operation of the recently designed construction of dampers, numerous final tests have to be performed, and the calculation itself is iterative, which considerably increases the complexity and a number of calculations. Stand design is suggested for carrying out these researches in a motorless way, while the modes and parameters of the torsional motions of the crankshaft match the operating modes of the combustion engine itself. Changeability of the distance between the motor masses and the type and magnitude of the torques acting on the motor masses makes the suggested stand universal for testing engines of any layout diagram. Torque modulation in amplitude, frequency, and phase is obtained by changing the appropriate electrical settings on the stator windings, creating torque for an equal torsional circuit. This circuit also enables testing only for resonant torque harmonics, which is an unquestionable advantage of the offered stand.

High rates of growth in the volume of earthworks in winter, with a lack of funds for the purchase of new equipment, determine the relevance of work to improve the existing and create new working bodies for the development of frozen grounds and snow-ice formations to increase the efficiency of their destruction without increasing the power of the base machine. This can be done by installing a fundamentally new cutting tool in the form of elliptical circular knives on the working bodies. The article deals with the kinematics of an ellipsoidal disk working body. Expressions for determining the displacement, velocity and acceleration of the point of the cutting edge of the disk are obtained analytically. It was found that the points of the cutting edge of the disk move in space along a complex trajectory, and the absolute values of velocity and acceleration are variable parameters. The regularity of the change in the angle of entry of the disk into the ground at different values of the angle of its attachment to the shaft of the working battery was revealed, and the main design and technological parameters were determined and substantiated.

This study aims to exclude the possibility of pile driver capsizing due to exceeding slope of the construction site surface. The paper determinates the reasons for the violation of the requirements of urban planning legislation and regulatory and technical documentation, which results in a pile driver capsizing. The authors calculated the center of gravity of the pile driver and its lateral stability during the preparation of piles for driving and the driving itself. The significance of the results for the construction industry lies in the need to increase the level of safety when performing pile work and taking into account the actual conditions of the site in the places of their implementation. At the investigated construction site, the slope of the construction site did not exceed a guaranteed safe value 3°.

Technical means used for soil surface treatment do not fully meet the technical requirements for high-quality soil treatment. In order to solve this problem more effectively, various rotary machines with working bodies that perform complex spatial movement are currently being developed. But, as practice has shown, that the work of these tools is unstable and that the cultivation of the soil is carried out unevenly. To eliminate these disadvantages, we developed a tillage tool with ellipsoid disk working bodies mounted on the shaft at a strictly defined angle [7, 13]. The analysis showed that to ensure the efficiency of work and reduce the traction resistance of tools for tillage, it is necessary that the angle of installation of the ellipsoid disk abount rotation axis is also optimal. Here are the results of experimental studies of the traction resistance of disks conducted in the conditions of a soil channel. The mathematical model of the technological process was obtained by processing experimental data in the computer program “Statistica” and presented in the form of multiple regression equations in encoded and real physical quantities. The response surfaces are constructed based on the obtained equations.

The influence of the design parameters and technological properties of the ground on the nature of the oscillatory movement of the blade of the working body of the earth-moving machine is investigated. The purpose of the study is to identify the force factors of the interaction of the oscillatory working body of the earth-moving machine with the ground and determine its optimal parameters. The equation of the oscillatory motion of the blade of the working body of the earthmoving machine depending on its design parameters and technological properties of the ground is obtained. The results can be used in the development and determination of the optimal design parameters of the working bodies of earth-moving machines.