Abstract: The invention relates to dynamical sealing systems for rotating pairs and can be used, in particular, for sealing of the bearing supports of cutter drill bits. The sealing (packing) ring has the cross-sectional cut of four-cornered shape, formed with the outer and inner cylindrical surfaces, including the side (end) surfaces, which define the ring height. The sufficient improvement of the efficiency and the service life of the sealing system are ensured, due to closed (dead-end) feed and drain lubricant grooves being provided on the working, sealing surface, and their inlet and outlet openings are positioned on the ring opposite surfaces bordering on the working surface. The outer, inner or end surface of the ring can serve as the working, sealing surface.

Abstract: The proposed device relates to roller drill bits with air drilling capability and can be used for drilling of rocks of high hardness. The drill bit includes a body and rock-destroying elements with cutting equipment mounted on the body one inside the other by means of bearing supports, wherein the inner element is located at an angle relatively to the axis of the drill bit, and the outer element is located in the opposite direction of the axis. The device provides for an increase of the service life, high efficiency, and interchangeability due to a special design, which envisages the cutting equipment formed as replaceable jet nozzles made of hardwearing material and provided with arm insertions, preferably made of wolframite-cobalt based alloy, wherein the bearing support of each rock-destroying element is furnished with a unit adjusting the axial play value of the rock-destroying elements.