The developed first stage of a complex energy method for determining energy losses in an electromechanical drive experiencing random dynamic loads is presented. The method is based on the combination of calculation and experiment to determine the losses in the range of real loads overcome by the drive. The method is practiced on a serial hydraulic drive of a harvester feeder of the URS type.

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.

Operation of mining machines at mines and surface mines according to the existing regulations involves the following operations: machine acceptance at the factory, transportation to the face, installation, maintenance, use of machines in the face for their intended purpose, current and major repairs, dismantling.

Currently, the power of drives (motors and gearboxes) of harvesters has increased dramatically.

When a combine harvester operates at a rational cutting speed, maximum productivity is ensured at given values of resource and safety indicators. These conditions will be met if the optimum thickness of the "chip" is provided, which determines the ratio of the dynamic component of the load and friction power.

Coal mining in all basins of the country is provided mainly by mechanized complexes with narrow-capture harvesters. In many lions their productivity reaches 1000 tons and more of coal per day.

The power and productivity of shearers are increasing from year to year. The average level and range of fluctuations of loads consumed by the machine drive are growing....

For a number of years, the staff of the Department of Mining Machines Design and Mechanical Engineering Technology of LMI has been carrying out load cells of mining shearers in various coal basins of our country ...

Technical and economic indicators of mines increasingly depend on the efficiency and reliability of mining combines. The operation of mechanized complexes, and thus the mine as a whole, depends on the combine harvester productivity. The capacity of narrow-capture harvesters is continuously increasing, but their productivity is growing insufficiently, and the accident rate remains high. ...

During 1967-1970, the operation of wide- and narrow-capture harvesters was studied at Norilsk mines. During the tests, the average and instantaneous values of power consumption P, current I, feed rate v_n and feed force F_п were measured. Special sensors and recording equipment were made to record these parameters. One of the tasks of the tests was to establish the dependence of the harvester productivity on the extracted power of the formation.

Productivity of mining harvesters largely depends on the efficiency of the feed drive, providing the machine movement during operation and maneuvering operations. The complexity of the design, high class of manufacturing accuracy and the need for high reliability, especially when working in mechanized complexes, require a thorough inspection of the feed drive assembly before the machine is lowered into the mine. Such a check can be carried out on test benches. Thus, at the ore-repair plant named after V. I. Lenin. V. I. Lenin ore-repair plant combine “Tulaugol” very carefully tested repaired feed drives G-404.

Unmanned excavation of coal is possible only with automatic control of the position of the executive body of the mining machine according to the power of the seam. Reliable operation of drilling machines, as well as other drilling machines, at considerable depth of boreholes can be ensured only by effective sensors determining the boundary “coal - rock” in the borehole. Creation and implementation of workable automatic devices that control the position of the executive body of mining machines and depending on changes in hypsometry and formation power, is of great importance.

At present the industry of the Soviet Union mass-produces only Ural-33 type punching machines, which are used in those mines, where it is impossible to use harvesters. With the existing technology of oil shale mining, the undercutting is made at the bed soil (on the third layer of oil shale) by the machine “Ural-33” with a two-meter bar, with a useful furrow of 1.9 m ...

The existing technology of oil shale extraction provides for simultaneous extraction of the entire industrial oil shale stack. This provides the fastest and least labor-intensive destruction of oil shale and allows for mechanized loading in chambers - longwall faces in the case of bulk excavation. However, this method leads to mixing of oil shale and rock, and manual sampling in longwall faces is very labor-intensive and unpromising in terms of increasing labor productivity ...

In 1964-1965 at the mine No. 3 of Slantsy Combine the resistance of layers of the industrial oil shale stack to mechanical destruction was determined. Resistance (strength) was determined in three ways: 1) by the method of pushing with the help of the POC device (strength coefficient f); 2) by the method of cutting from the open face with the help of the DKS-3 device (strength index A); 3) by the energy indicators of the Ural-33 cutting machine (strength index Avr)....

The tests were carried out in 1965 to determine the efficiency of destruction of layers of industrial oil shale stack by the executive body of the combine, which is a milling-type rebound crown. The rotation speed of the crown is 58 r/min from the electric motor KOF-22-4k (25 kW). Rotation of the crown in the vertical, horizontal planes and feed back and forth (0,5 m) are carried out by hydraulic cylinders. Two hydraulic jacks provide the harvester's support between the roof and the soil. The hydraulic jack pumps are driven by the second electric motor KOF-22-4k. Thus, the total installed power of the motors for rotation and feeding of the crown is 50 kW ...

For the drives of electric motors are used asynchronous squirrel cage motors with a deep groove and double squirrel cage.The difference in the operation of electric motors of cutting machines is that they are included in the “non-rigid network”. At present the distance of the electric motor from the area transformer and the power of the electric motor itself are limited by the values of permissible voltage drops during operation and start-up of the electric motor.