The article addresses directions and horizons in the creation of highly efficient specialized continuously operating earthmoving machines and provided a technical proposal for the multipurpose earthmoving machine. Study subject: continuously operating earthmoving machines. Objective: To create a power-efficient special-purpose earthmoving machine. Study method: experimental. Existing dimension-types of trenching excavators allow digging lengthy excavations of the assigned profile with minor deviations from their nominal width and depth. Creating of excavations of different profiles is being achieved via machine re-equipment with different implements. A sustainable solution is to create multipurpose earthmoving machines that are capable to perform lengthy excavations of various widths and depths with the same implement and without constructional alterations. There are known machine designs for trenching on the basis of a wheeled tractor with a mounted chain-bucket implement that is able to perform the lateral oscillatory displacements in relation to the vertical axis on the hull back of the tractor. Alteration of the implements oscilative motion amplitude allows to excavate the tranches of differnt width. This is the essence of the multipurpose earthmoving machine. The existing kinematics chain sections of the implement in relation to the tractore can't ensure the consistency of the machine load due to inconsistency of the borings along the width of excavation. This leads to significant pulsation of the load on the implement, loss of the longitudinal stability and, in the end, reduces the potential productivity of the machine by half. We have performed a set of studies in creating of the multipurpose earthmoving machines (MEM). As the experimental study objects we've used physical models of the MEM implements and full-size prototypes of the machines. Results of the study experimentally confirm the possibility to create a highly productive MEM with rotary implement, which efficiently performs trenches as well as wide construction pits in the mode of reciprocating approach of the rotary implement to excavation by means of equalization and minimization of power load parameters values. KEYWORDS: EARTHMOVING MACHINE, ENERGY INTENSITY, KINEMATICS, PRODUCTIVITY, SOIL

This article addresses the creation and optimization of designs for Universal Continuous-Action Earthmoving Machines (UCAEM) capable of excavating extensive trenches of various widths, depths, and shapes without structural changes to the operating equipment. The paper provides a detailed rationale for the relevance and practical feasibility of developing continuous-action universal earthmoving machines. Analytically, the required trajectory of movement for the soil excavation operating element of UCAEM in the process of constructing wide trenches (excavations) in the soil is determined. This trajectory resembles a Bernoulli lemniscate, along which the operating element of UCAEM moves to excavate the soil in evenly thick planar chips. This enables the construction of trenches in the soil with maximum work productivity, minimizing external loads on the earthmoving machine's operating element. To implement the above, a physical model of the rotary operating equipment of UCAEM was created, and experimental studies were conducted. The design of the UCAEM operating element movement drive is based on a two-circuit lever mechanism with fifth-class rotary pairs, providing the delivery of the soil-excavating operating element to the soil face. Soil excavation is carried out in the mode of fan-linear feed of the operating element to the face. The movement of the operating element in the face is performed by a lever mechanism with three degrees of freedom, each link of the mechanism is provided with an individual turning drive using a pair of hydraulic cylinders relative to the hinge of its attachment. An algorithm for the operation of the drive for the movement to the face of the two-circuit soil-excavating rotary operating equipment of continuous-action UCAEM has been synthesized, providing soil excavation with chips of uniform thickness in plan, regardless of the width of the trench, and consequently, increasing the productivity of the machine's operation. Equalization of the chip thickness in plan is achieved by turning the intermediate frame of the operating element at the end of each half-cycle of the working process. An algorithm for the movement of the operating element during the construction of entry and exit ramps during the construction of trenches in the soil over several passes of the operating element has been justified.

This article considers external loads experienced on the rotor actuator of the universal continuous earthmoving machinery when digging wide excavations (ditches) in the soil and the ways to improve its productivity. Under the condition of translational and rotational supply of the soil-developing actuator to the face, the possibility of minimizing and leveling external loads on the actuator by improving the kinematics of its cyclic movement in the face has been experimentally proved. The actuator should move according to the required trajectory, which corresponds to the curve of the lemniscate of Bernoulli. The load of the UEM soil-developing actuator, operating in the mode of digging the soil, and the effectiveness of the suggested method for leveling the external loads have been experimentally assessed on the current physical model of the operating equipment. Leveling and reducing the absolute values of loads on the UEM operating equipment is achieved by improving the actuator trajectory optimization when digging the soil. It implies the additional rotation of the actuator intermediate frame at the end of each half cycle of the operating process. The required duration of the additional rotation of the intermediate frame is functionally dependent on the actual speed of machinery movement. The additional rotation of the intermediate frame, the duration of which is 1.1 s in the mode of maximum productivity, reduces the maximum load of the operating equipment, namely: torque on the rotor axis M_t-by 19% (up to 60 kN m), the components of the main force vector: vertical force-by 9% (up to 40 kN), and lateral force P_l.m-by 32% (up to 58 kN). The obtained results enable to comprehensively assess the maximum load of the UEM operating equipment under the conditions of changing values of the factors on which it depends and to objectively assess the directional stability of the machinery. Aligning the thickness of the shavings cut by the buckets of the rotor actuator in a half-cycle enables to improve the productivity of the universal earthmoving machinery almost twice.

Problem. From the analysis of the technical literature, it was established that among the trenchless technologies for laying underground engineering communications and service pipelines, the technology with the possibility of forming a horizontally directed communication cavity in the soil using soil-piercing installations of static action is the most common. Goal. This method consists in forcefully pressing a soil-piercing working body, which has the form of a conical-cylindrical projectile, into the soil. At the same time, the well is formed by radial extrusion of the soil around the formed well. However, the use of such equipment does not provide high accuracy, which limits its practical application within 20 m. It is not sufficient for modern requirements of creating transitions during the laying of communications. Methodology. One of the ways to improve the efficiency of laying underground networks is to extend this method over a longer distance by correcting the trajectory of the working body. This is achieved by using a soil-piercing head with an asymmetric tip. Due to this, in addition to the axial resistance of the soil, a transverse component force appears, which deflects the head during its advancement in the soil. The question of determining the angle of displacement of such a tip is important in terms of the process control. Results. In the paper, a calculated dependence is proposed for determining the rational value of the angle of inclination of an asymmetric tip working surface, which is a flat plane cut at the angle of a cylinder. An analysis of the dependence of the angle of the working surface inclination on the physical and mechanical properties of the soil is also given. Originality. It was determined that the maximum angle of inclination of the frontal surface is determined by the conditions of soil descent from it. Its maximum value, for example when working in loam, should not exceed 55o-67o for a tip made of steel. Practical value. The obtained calculated dependence can be useful for determining the angle of inclination of the flat frontal surface of the tip of the soil piercing working tool for controlled static soil piercing at the stage of designing networks and choosing an effective method for drilling a well under roads or other obstacles.

Summary. This paper addresses the optimization of the structural parameters of the lifting mechanism of the frame for the working equipment in a universal rotary earthmoving trenching and excavation machine operating continuously. The goal is to reduce the efforts in its hydraulic cylinders while maintaining the prescribed kinematics of the mechanism. Structurally, the lifting mechanisms of the working equipment are designed with the hydraulic cylinder positioned above the boom (frame), and the fluid is supplied to the rod chamber of the hydraulic cylinder for lifting. The formulated optimization task aims to design a mechanism that could reach initial and final positions while simultaneously developing minimal peak effort on the hydraulic cylinder rod. Known as a "minimax" problem, this task seeks the minimum value among a set of maximums. Variables chosen include the linear distances from the axis of rotation to the hydraulic cylinder attachment points and the structural angle; a target function is defined. Computational dependencies for determining the design parameters and the force on the hydraulic cylinder rod are presented. Additionally, a constraint on the range of values for the structural angle parameter has been introduced. For calculations, a spreadsheet processor MS Excel with the "Solver" add-on was used. As a result of the optimization for the physical model of the working equipment of the universal rotary earthmoving trenching and excavation machine operating continuously, the parameters for the positioning of the hydraulic cylinder attachment points were found to reduce the load on the hydraulic cylinders by 1.39 times while maintaining the prescribed kinematics of the mechanism. The proposed methodology can be recommended for use in calculations of other lifting mechanisms where the cylinder is positioned above the boom and the fluid is supplied to the rod chamber of the hydraulic cylinder. Keywords: hydraulic cylinder, earthmoving machine, force, working equipment, force calculation, software, link-lever mechanism

This article is concerned with the physical substance of the interaction between the skid of the multipurpose earthmoving machines implement and the surface of the soil excavation and experimental determination of the power load parameters of the skid as a factor that ensures the cource stability of the machine during the excavation process. Study object: process of the power loading of the skid in the rotary implement of the multipurpose earthmoving machine. Objective: determination of the physical substance and values of the power load parameters for the skid in the rotary implement of the multipurpose earthmoving machine. Method – the experiment on the physical model of the implement. The experimental determination of the value and beavior of the power load on the skid of the machine’s implement during excavation in the mode of reciprocating approach in the absence of proven calculation methods should be concider the only way to evaluate the load on perticular assembly as well as on the machine as a whole. This is necessary for power balance evaluation for the machine that works in the soil excavation mode and for the determination of the course stability of the machine During the study we have concluded that the values of the skid power load components (longitudal, transverse, vertical) are mainly determined by forming and movement of the soil traction prism that spills to the bottom of the excavation during digging. To the outmost this effect manifests near the walls of the excavation that causes the plated shape of the skid bearing surface which ensures it’s ‘emersion’ above the prism of the spilled soil. We have determined the dependancy of the skid load forces from kinematic characteristics of the implements translation modes during excavation. The consistent pattern that we have detected allows to minimize the power load of the skid by tweaking the duration of the implements additional turn at the end of each half-cycle which leads to the increase of the course stability during creation of the of the wide excavations.