Piston pumps are widely used in the lubrication systems of mining machines. When carrying out technical maintenance (MOT), including lubrication and filling works, at the site of operation of mining machines due to the remoteness from repair shops and warehouses of fuels and lubricants (FAL), mobile repair shops ( MRS), maintenance units (MU) and mechanized filling units (MFU) are used. The specificity of carrying out maintenance is to create conditions for the supply of oils, working fluids and lubricants to the corresponding systems of mining machines for their refueling. Existing piston pumps and pumping units, as a rule, are single-flow, and the piston is driven by a crank mechanism driven from the engine through a worm gear. The emergence of unique, hydraulic, low-mobility mining machines in open pit mining required a significant increase in the power of the MU and MFU oil pumping units, primarily for greases. However, the traditional design of the drive design of a crank-type piston pump unit at a power of over 80 kW does not allow achieving the specified operating time, it is accompanied by intensive wear of the drive elements and increased dynamics during operation. In addition, it is necessary to apply various designs of pumping units for the supply of liquid and grease lubricants. Thus, it is necessary to develop new circuit solutions for pumping units of the crank type, to improve mobile refueling facilities with a modernized design of the pump unit drive of the mobile lubrication and filling station MRS.
The development prospects of the mining industry are closely related to the state and development of modern mining machinery and equipment that meet the technical and quality requirements of mining enterprises. Enterprises are focused on a quantitative assessment – the volume of mineral extraction, depending on the functioning efficiency of a promising series of mining machines, which include modern mining excavators. Downtime and unplanned shutdowns of mining excavators directly depend on the operating conditions of the mining machine, which has negative influence on the machine as a whole and its technical condition, which entails a decrease in the efficiency of using expensive mining equipment and economic losses of the mining enterprise. The rationale for external factors that affect the operating time and technical condition of mining excavators is given. For a more detailed assessment of the influence of external influences on the efficiency of operation of mining machines, the influencing factors are divided into two groups: ergatic, directly related to human participation, and factors of a natural-technogenic nature, where human participation is minimized. It was revealed that factors of a natural-technogenic nature have the greatest influence. An algorithm is proposed for a comprehensive assessment of the technical condition and forecasting of operating time both in nominal and in real operating conditions, taking into account factors of a natural and technogenic nature. It is proposed, based on the developed program for planning and evaluating the life of a mining excavator, to adjust the schedules for maintenance and repair (MOT and R) in order to minimize the number of unplanned downtime of a mining excavator and maintain it in good condition.
Domestically produced opencast excavators are shown to be serious competition for foreign hydraulic machinery. It is suggested to estimate the potential of an opencast excavator via its basic operation effectiveness factor equal to the ratio of the scoop payload to the nominal cost of excavator operations under its normal operational conditions. Comparing the theoretical values of standard operations of hydraulic excavators of the third type-and-size group during coal mining with domestically produced EKG-18R on their operation effectiveness factor shows that the excavator exceeds foreign hydraulic models from that group 2.7-3.3 times. Theoretical foundation is provided for a complex of factors that affect the operating time of single scoop open- cast excavators, a structure is offered for the model of comprehensive assessment of operating time for opencast excavators. Complex indicators are substantiated and proposed for supporting operational effectiveness of such excavators. Assessment is offered of operational effectiveness of EKG-18R excavators following the criterion of energy consumption per excavation of a unit of rock mass. Generalization analysis is given of a set of factors that affect the value of operating time for EKG-18R excavators. Proposals are put forward on upgrading the regulations for technical maintenance and repairs of EKG-18R excavators. The task of assessing the technical state of machinery calls for using integral criteria that would enable one to identify the current technical state and the residual resource of machine aggregates, their failure potentially resulting in emergency situations accompanied by considerable property damage. It is feasible to use an integrated indicator of the degree of degradation of s machinery item for such an integrated indicator, retrieved in the course of assessing the current technical state of that item during diagnostic procedures. In its turn, such and integral indicator of the state of an item is defined by the averaged value of diagnostic indicators reduced to their basic values with the account of their individual weight factors.
To date, there is need to review the existing rigid system of preventive maintenance and the transition to a more progressive system, which provides maintenance and repairs on its actual state, in which the need for repair work is based on a preliminary examination and the results of the diagnosis and monitoring of major nodes excavator. Pays special attention to the concept of TPM (Total Productivity Maintenance) for the maintenance of mining excavators.
The effect of local changes in the surface hardness of the end surfaces of teeth of coarse-grained gear transmissions mining machines. Represented by patterns of change of the surface hardness is not the type of reference to the loading. The estimation of the value of destruction of samples. Proposed to assess the remaining amount of coarse-grained gears with consideration of changes in the local surface hardness developed technique.
This paper provides an overview of the current analysis of peat resources distribution of Northwest Federal district. The analysis of peat industry is resulted. The power effective technology of career extraction of peat raw materials and manufacture of agglomerated peat fuel for needs of the distributed power is offered.
In article the review of methods of a theoretical estimation of a resource of elements of cars is presented. Perspectivity of the thermodynamic approach is shown at the analysis of an expenditure of a resource by system elements. Presented a probabilistic approach in determining the energy source.
The reasons of an emergency stop of tubular furnaces is destruction of bearings in support of the furnace, bearings and cogwheels in mechanical transmission, failure the electric motor, infringement of integrity of the case of the furnace and it brickwork. In article possibilities on forecasting of a residual resource of bearings of support and transmission are considered, principles of construction of a complex from system of monitoring of a condition and automatic systems of greasing of bearings are offered.
To reduce the use of manual labor in mining peat from deposits with the decrease of anthropogenic impacts on the environment has been developed the device with rational parameters allowing to produce therapeutic peat. In order to improve the performance proposed to use the screw with the optimal angles rise to transport both frozen and thawed peat.
Ways to raise service life of open tooth gearings on an example of a drive of a spherical mill are considered. Results of introduction of automatic system of greasing are resulted and increase ways efficiency of its uses are offered.
Lubricating value shows loading capacity of transmission oil. Poor lubricating value of friction couples which are used at borderline lubrication ordinary have wear-out areas and these friction couples also fiercely attacked by corrosion. That’s why a decision of choosing oil type have to be substantiated. In this article rapid method of lubricating capacity tests is offered.
It is shown, that application of the combined displacement while designing toothed gearings considerably allows to expand area of existence of gearing with a non-standard radial backlash. Influence of parameters of the tool on area of existence of gearing is submitted, the technology of realization of tangential displacement by generation of gears is described.
For diagnosing transmission of the mountain machine without installation of expensive gauges pilot diagnostics on parameters of a feed of the electric motor, based on the assumption can be used, that the majority of the indignations arising in transmission and influencing at the moment of resistance, overcome by the engine, affects change of instant power consumed by the electric motor.
Presented the practical useful of central oiling systems (COS) for equipment mining and building industry and determined the field using of these systems. Presented the experimental results of flooding different oil for COS bellow zero.
Advanced diagnostic and monitoring devices are required to carry out timely maintenance and repair of mining equipment and to reduce the number of emergency shutdowns. The article presents a comparative analysis of vibration and acoustic emission diagnostic techniques.
The article describes the history of the formation and development of the Faculty of Mining and Electrical Engineering at the St. Petersburg State Mining Institute. Its current state is described. Information about leading scientists, founders of the faculty is presented.
Application of the combined displacement when designing gears allows to considerably expand the area of existence of meshing with non-standard radial clearance. The influence of the parameters of the rack-shaped producing contour on the region of the meshing existence is shown, the technology of the tangential displacement realization during gear cutting is described.
Extensive opportunities to influence the properties of involute gears are available with combined displacement of tooth profiles - a combination of radial and tangential displacements, including the use of cutting tools with a standard initial contour. In particular, by combined displacement, the bending strength and wear resistance of cylindrical gear teeth can be increased by one and a half to two times, which is commensurate with material replacement.
Design schemes of pneumatic, hydraulic and drilling machines with combined drive, used in mines and mines, mainly have mechanical drives of drilling rod rotation. This refers to machines of domestic and foreign production. A considerable part of failures of drilling equipment occurs exactly due to the fault of rotary units. One of the weak points of the design is often the transmission output shaft support unit made on the basis of plain bearing. The energy and life of such a sliding bearing is limited by the limit value of wear, leading to the occurrence of unacceptable misalignment of the gear wheels’ axes. The expression for determining the energy resource of the plain bearing from the condition of permissible volume wear of the liner material is proposed.
The main results of research work performed at the departments of the mechanical cycle of the Faculty of Mining and Electromechanics in 2000 are presented. Research and design works for making effective and environmentally safe machines and complexes for mining and processing industries are made at the Faculty of Mining and Electromechanics under the guidance of leading experts. The analysis of design and operating characteristics of manufactured dump trucks is given and modern principles of formation of design and operating requirements to them are formulated. A methodology and mathematical model for determining the optimal characteristics of the complexes have been developed. Studies on the development of hydraulic transport equipment for underwater development of offshore mineral deposits have been carried out. New technological schemes of slurry hydrotransportation in flexible sectional pipelines of variable curvature united by spherical joints are proposed. Research work on the development of the theory of working processes and improvement of electromechanical mining equipment complexes for energy-saving technologies was carried out.
Изложен разработанный первый этап комплексного энергетического метода определения потерь энергии в электромеханическом приводе, испытывающем случайные динамические нагрузки. Метод основан на сочетании расчета и эксперимента по определению потерь в диапазоне реальных нагрузок, преодолеваемых приводом. Метод отрабатывается на серийном гидроприводе подачи комбайна типа УPC.
Широкое распространение шестеренных гидромашин, и в частности гидронасосов, объясняется их высокой технологичностью и простотой конструкции. Однако наличие защемленного объема шестеренной гидромашины, обусловленного реализацией зоны двупарного зацепления при коэффициенте перекрытия ε α > I , ведет в снижению объемного КПД гидромашины, а также требует технологических и конструктивных мероприятий по разгрузке защемленного объема, что в конечном счете сказывается на трудоемкости изготовления пгдромашины, снижает ресурс работы ...
В зависимости от конструкций шестеренных гИдромашин их используют в качестве насосов, моторов и делителей потоков при давлении до 28-30 МПа в силовых гидросистемах машин. В диапазоне давлений 0,3-2,5 МПа применяют насосы в системах смазки двигателей, трансмиссий различных рабочих машин, в компрессорах. Шестеренные насосы применяют также для перекачки и транспортировки жидкостей и квазижидких сред с температурой до 250 °С и вязкостью 1-3800 сСт, включая агрессивные и абразивные среды ...
Задача внедрения клина в деформируемую преграду решалась многими исследователями применительно к работе бурильных машин, струговых установок, добычных комбайнов и другой аналогичной техники, т.е. для условий, когда клин на своем острие испытывает больше сопротивления при внедрении в разрушаемую породу ...
Одной из актуальных, влияющих на эффективность горного производства проблем, является подготовка горной массы в погрузке. Эта проблема включает не только работы по дроблению горных пород массовым взравом, но и разрушение негабаритных кусков ...
