Expansion of application range of pneumatic hammers with adjustable impact effect

Abstract The author reviews briefly existing machines for trenchless laying of underground utilities and vertical driving of steel elements in soil. For a pneumatic hammer with ring and inertia valves for driving different diameter pipes, arrangement and operating principles are described. Powerful longitudinal forces generated by shocks ensure destruction of solid rocks or compaction of soil in the zone of hole-making. These forces can be used in implementation of other technologies as well. For instance, maintenance and rehabilitation of oil well centrifugal pumps, which requires complete disassembling of the machine. For taking of many parts (impellers and guide vanes) out of a hole (a pipe), a pneumatic hammer with piston weight of 40 kg was tested. Another application area of pneumatic hammers can be stimulation of caking material unloading from railway cars using a vibropercussion plant driven by pneumatic puncher. Replacement of the latter by a pneumatic hammer of the same size and performance can enhance efficiency of the process.