Vol 138

Exploration and industrial development of seabed resources is impossible without technical means and, first of all, underwater mining equipment. An important role among underwater mining machines is assigned to these units carrying mining and geological exploration working bodies in the form of suction tips, rippers, buckets, picks, dumps, soil pumps, erlift heads, probes, impellers, dies, etc. The main role of these units is played by the underwater mining equipment.

Large-module involute gears are widely used in heavy, transportation, mining, road construction and chemical engineering. However, the calculations of contact strength and endurance of the active surfaces of the teeth of such gears poorly reflect their features.

Widespread use of gear hydraulic machines, and in particular hydraulic pumps, is explained by their high manufacturability and simplicity of design. However, the presence of the pinched volume of the pinion hydraulic machine, due to the realization of the zone of two-pair meshing at the overlap coefficient ε_α>I, leads to a decrease in the volumetric efficiency of the hydraulic machine, as well as requires technological and design measures to unload the pinched volume, which ultimately affects the labor intensity of the manufacture of the hydraulic machine, reduces the resource of operation.

Cylindrical and tapered surfaces can be joined by means of interference fit. This type of mating of parts is called a guaranteed interference fit. It is characterized by simplicity and manufacturability, possibility of application in mass production, good mutual centering of parts and load distribution over the entire seating surface.

Traditionally, it is customary to determine the capacity of a jaw crusher based on the volume of the so-called dropout prism in the limiting zone. In case of straight jaw outlines, this zone is located at the very bottom of the working space. It is assumed that the material is discharged only when the movable jaw is moving away. As the jaws move closer together, the material is crushed and no discharge takes place.

The need to solve such problems arises, in particular, in the design of reloading and loading chutes and funnels with a given final velocity of bulk cargo and the direction of the vector of this velocity, as well as in the design of unloading units of the transported cargo through the end (head) drums of belt conveyors.

Constant growth of technological preparation of production and increase of requirements to the developed parameters and standards stipulates the necessity of wide use of modern computing means in the practice of technological calculations. A number of domestic analog devices have been created, which allow to determine numerical values of cutting parameters for machine tool operations. General machine-building standards of cutting modes presented in the form of functional dependencies obtained by approximation of the corresponding normative tables are taken as the initial normative base.

Drill rods made of hexagonal hot-rolled steel of 55C2, 3OHGSFA, 12XHZA, 30XMA, 28XGNZM, 40X2AUF and others break during perforator drilling. The rods break in the areas of shoulder, shank, cone part, as well as along the length of the main part of the hexagon. The most frequent breakages occur in the bump zone, which is obtained by hot-drilling on boring machines.

The advantage of briquetting over such pelletizing and sintering processes is that briquetting allows to obtain a product of strictly regulated dimensions, and no chemical transformations take place in the initial mixture during the briquetting process. In addition, this process is the most favorable from the point of view of sanitary requirements.

The St. Petersburg Mining Institute has carried out a number of works in which a wide enough area of use of spiral-chain gearing in the drive of mining machines is defined, a methodology for calculating the main design parameters is developed, and also experimental data of laboratory and industrial tests of hoisting and transporting vehicles with a spiral-chain traction device (SCTD) are obtained, which have found application at mining enterprises of the Krasnoyarsk region. However, ensuring safer operating conditions of mining machines with SCTD requires additional studies of the influence of external factors on the process of converting the rotary motion of the working body into translational movement of the vehicle.

Depending on the design of gear hydraulic machines, they are used as pumps, motors and flow dividers at pressures up to 28-30 MPa in power hydraulic systems of machines. In the pressure range of 0.3-2.5 MPa pumps are used in the lubrication systems of engines, transmissions of various working machines, in compressors. Gear pumps are also used for pumping and transportation of liquids and quasi-liquid media with temperatures up to 250 ° C and viscosity 1-3800 cSt, including aggressive and abrasive media.

The operating mode of the mining machine is selected on the basis of maximum productivity at an acceptable level of dynamic load. Achieving the maximum permissible feed rate determines the optimum between the average and instantaneous loads, hence the permissible level of dynamics.

The AMS unit (mechanized aggregate with shandoor support), developed by SCTB Glavtonnelmetrostroy, is designed for complex mechanization of single-wall tunneling of metro stations. The AMS unit, which is a modernization of the AMK-I (K - calotte) unit, which worked in 1984 during sinking of the upper vault of Prospect Bolshevikov station, was manufactured in 1988 at Proletarsky Zavod by order of Lenmetrostroy. This is the first mining machine in the Russian practice, where along with the use of hydraulic drive in its feed mechanisms the electro-hydraulic drive of the actuator was used.

The technology of construction of single-wall stations of the St. Petersburg Metro provides for the development of the station core, which contains the bulk of the rock excavated during the construction of the station, after the construction of the upper vault. Until recently, this work was carried out mainly with the help of jackhammers.

The efficiency of mining machinery use is assessed by three indicators: productivity, resource and safety criteria, which determine the quality of mining, transportation, stationary and enrichment machines and depend on the ratio of their permissible and actual loads.

Increase of productivity and safety of works in mines and mines, at construction of tunnels and subway lines is possible only at complex mechanization of works, when not only main operations of technological cycle (extraction of minerals, carrying out of excavations), but also all accompanying auxiliary works are mechanized: excavation of recesses, cutting of faces, carrying out of sidings and auxiliary excavations of small cross-section.

Existing methods of belt conveyor calculations use high values of belt safety factors: from 8 to 10. This indicates the approximation of calculations, in particular, due to the fact that the dynamic forces in the belts arising at start-up (stopping) of conveyors are not taken into account. Taking into account the dynamics of belt tension is especially important for the calculation of multi-drive, long conveyors, where the drive stations are built into the inter-belt space and dispersed along the length of the conveyor. This would contribute to a more accurate selection of belt types and allow to obtain economic benefits from the installation of belts of lower strength or from the reduction of the drive slip time.

Errors in the manufacture of parts and assembly of units: deviations from the alignment of cylindrical and conical surfaces, deviations from the perpendicularity of the ends, arbitrary, random distribution of the gap in the interface and the associated displacement of the part and other similar, are characterized not only by the magnitude but also by the direction.

In the mining and processing of coal, ores of ferrous and non-ferrous metals, construction raw materials and other minerals, huge volumes of natural, materials are subjected to destruction to bulk.

Heavy-duty mining dump trucks have two main damping systems: air-hydraulic suspensions and tires.

High capital intensity and weight of mining machines set the task of maximum reduction of operating costs, including the costs of installation and dismantling works (MDR). The task is to choose a criterion for evaluating the effectiveness of new MDR technologies and means of their technical realization. The formation of such a criterion involves the use of elements of praxeological analysis based on the study of the effectiveness of actions performed by analyzing the relationship between the goal and the result of the action.