Ultrasonic/Sonic Driller/Corer as a hammer-rotary drill

摘要

Rock, soil, and ice penetration by coring, drilling or abrading is of great importance for a large number of space and earth applications. Proven techniques to sample Mars subsurface will be critical for future NASA astrobiology missions that will search for past and present life on the planet. The Ultrasonic/Sonic Drill/Corer (USDC) has been developed as an adaptable tool for many of these applications [Bar-Cohen et al, 2001]. The USDC uses a novel drive mechanism to transform the ultrasonic or sonic vibrations of the tip of a horn into a sonic hammering of a drill bit through an intermediate free-flying mass. For shallow drilling the cuttings travel outside the hole due to acoustic vibrations of the bit. Various methods to enhance the drilling/coring depth of this device have been considered including pneumatic [Badescu et al., 2006] and bit rotation [Chang et al., 2006], The combination of bit rotation at low speed for cuttings removal and bit hammering at sonic frequencies are described in this paper. The theoretical background and testing results are presented.