Research on Drilling Rate Optimization of a UCS Identification System While Drilling for Coal Mine Roadway Roofs

In this paper, to identify the roof unconfined compressive strength (UCS) in the process of coal mine roadway support in real-time and optimize the real-time drilling speed while drilling, this paper proposes and establishes a drilling test method for assessing the uniaxial compressive strength (UCS) of a roof. This method can be used to optimize the speed of drilling. Moreover, a mathematical model of the power output is developed for a roof-strata identification system with a drilling test system. The results were as follows: (1) the system was able to identify the uniaxial compressive strength of roof rock; (2) the pressure of the drill leg of the pneumatic bolt did not match the output power of the pneumatic motor, the pneumatic motor could not reach the maximum power point, and the insufficient thrust of the pneumatic leg led to failure of the maximum output power of the pneumatic motor; (3) to increase the output power of the air motor and thus improve the drilling speed, we applied a booster valve for the system. The experimental results show that the power of the air motor has a linear relationship with drilling speed. In this way, the speed of the drill can be increased by increasing the motor power.

GROUNDING PARAMETERS OF THE MILKING MACHINE PULLER

Проблема и цель. Теоретические исследования направлены на возможность расчета расхода воздуха и мощности пневмодвигателя съемника аппарата с вымени животного. Методология. Холостое доение доильным аппаратом весьма опасно для коров, так как помимо болевых ощущений на сосках вымени часто приводит к заболеваниям животных и их преждевременной выбраковке. Таким образом, важно не только полностью выдоить корову, но и вовремя отсоединить подвесную часть доильного аппарата от вымени животного. Для устранения холостого доения авторами предложена конструкция съемника, обеспечивающего отсоединение подвесной части доильного аппарата от вымени коровы по окончании доения автоматически. Он состоит из пневмодвигателя с редуктором и нити, намотанной на барабан. Результаты. При теоретическом рассмотрении работы съемника аппарата были выявлены аналитические зависимости расхода воздуха пневмодвигателя съемника от частоты вращения ротора пневмодвигателя, количества его лопаток и значения вакуума в вакуумпроводе. Выявлено, что с увеличением вышеуказанных параметров увеличивается и расход воздуха съемником. Авторами также проведены теоретические исследования, в результате которых определен ряд параметров пневмодвигателя: мощность и частота вращения барабана пневмодвигателя в зависимости от размеров барабана, расстояния размещения съемника от пола, угла наклона подвесной части и ее массы. Заключение. Результирующие формулы позволяют определить требуемую мощность на валу барабана и частоту его вращения для съема аппарата с вымени без падения на пол. Problem and purpose. Theoretical studies are aimed at the possibility of calculating the air consumption and the power of the pneumatic motor of the device puller from the udder of the animal. Methodology. Blank milking with a milking machine is very dangerous for cows, since in addition to painful sensations on the udder teats, it often leads to diseases of animals and their premature culling. Thus, it is important not only to milk the cow completely, but also to disconnect the hanging part of the milking machine from the udder of the animal in time. To eliminate blank milking, a puller is proposed that automatically disconnects the hanging part of the milking machine from the udder of the cow at the end of milking. It consists of a pneumatic motor with a gearbox and a thread wound on a drum. Results. When considering the operation of the puller, analytical dependences of the air fow rate of the puller pneumatic motor on the rotational speed of the air motor rotor, the number of its blades and the vacuum value in the vacuum line were revealed. It was found that with an increase in the above parameters, the air consumption of the stripper also increased. There were also studies, as a result of which a number of parameters of the pneumatic motor were determined. They included the power and rotational speed of the drum of the pneumatic motor depending on dimensions of the drum, the distance of the puller from the foor, the angle of inclination of the suspension part and its mass. Conclusion. The resulting formulas make it possible to determine the required power on the drum shaft and its rotation frequency for removing the apparatus from the udder without falling to the foor.

Pneumatic Hybrid Power Plants Efficiency

Tightening environmental requirements and rising fuel prices are forcing developers to look for ways to improve the efficiency of vehicle engines. The use of a combined power plant with more than one energy source is the most efficient. Therefore, there is a need to improve the efficiency of pneumatic hybrid power plants by utilizing thermal energy emitted into the atmosphere with exhaust gases and energy removed from the cooling system of an internal combustion engine. One of the possible systems for using the heat of an internal combustion engine exhaust gases is the combined power pneumatic with separate gas flows which is a piston pneumatic motor with internal heat supply. The pneumatic motor with internal heat supply is based on the PD-10U (ПД-10У) two-stroke starting engine, from which the standard fuel and ignition systems were dismantled. A crankshaft driven pneumatic valve is mounted on the cylinder head. During the research work the polynomial equation was obtained. It allows to assess qualitatively and quantitatively the influence on the effective power, generated by the pneumatic engine, of the compressed air supply system adjusting parameters, cylinder walls temperatures, as well as the temperatures of exhaust gases, entering the cylinder from internal combustion engine