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The paper considers one of the promising shut-off and control elements of the air distribution system of pneumatic impact machines - an annular elastic valve (CUV). This element allows you to reduce the energy consumption of pneumatic devices. Unfavorable combinations of factors that hinder the movement of the valve necessary for sealing the working chamber are considered. The paper presents a method for calculating the elastic valve that controls the release of energy from the return chamber of the pneumatic impact machine, which allows determining the main geometric dimensions of the valve device at the design stage, which provides a stable self-oscillating cycle of the pneumatic impact machine with the specified energy characteristics. The developed technique was used in the modernization of the air distribution system of the ring impact machine (KUM), designed for immersion of rod elements in the ground. Tests of the resulting sample in production conditions confirmed the increase in energy performance compared to previously produced machines of a similar type.

This paper presents the design of portable downhole hammers for borehole diameters of 43 and 76 mm when drilling with a combined rotary-percussive method in coal mines. The scope of use is described. Features and advantages of prototypes are shown. The characteristics of DHH and research data are given. The conditions of production tests and operating results are described.

The design of a domestically produced DTH hammer for drilling holes in rocks of medium and high strength is presented. Using the mathematical modeling method, the serviceability of the hammer at an energy source pressure of 2.4 MPa is proved. The results of DTH hammer prototype testing at lab and full scale are presented.

The article describes bench tests and calculations aimed to determining effect of parameters of ring-type elastic valve on variation of average pressure in the valve clearance. The results allow refinement of the design model of ring-type elastic valve and correction of the elastic ring cross-section based on the determined mechanisms.

The article describes computer modeling of three options of pneumatic percussion unit in a circular impact machine. All options have similar structure diagrams and mechanical linkage parameters but different control of energy-carrier feed in a working chamber: valveless; with one or two circular elastic valves. The obtained data allow quantitative evaluation of operation of such systems given the accepted constraints for mechanical block.

The authors discuss general schemes of air percussion machines equipped with ring-shape elastic valves, substantiate parameters of an elastic valve calculation model, derive relations for the valve sizes, material characteristics and actuation pressure, as well as present results of experimental estimate for the behavior of a material the valve is made of.