Sonic drill head
AssigneeLongyear TM, Inc.
InventorsKristian S. Drivdahl, Robert Eugene Able, Todd A. Nevenner, Kenneth Carl Altrichter
Life of this patent
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Abstract
A drill head assembly includes a shaft having a shaft axis, an oscillator assembly operatively associated with the shaft, the oscillator assembly having at least one eccentrically weighted rotor configured to rotate about a pivot point to generate an oscillating vibratory force, wherein an oscillation centerline is defined transverse to the shaft axis and including the pivot point. The drill head assembly also includes a lower bearing coupled to the shaft on a first side of the oscillation centerline and an upper bearing coupled to the shaft on a second side of the oscillation centerline, the second side being opposite the first side.
Claims22
A drill head assembly, comprising:
- a shaft having a shaft axis and a plurality of external threads;
- an oscillator assembly operatively associated with the shaft, the oscillator assembly having at least one eccentrically weighted rotor configured to rotate about a pivot point to generate an oscillating vibratory force, wherein an oscillation centerline is defined transverse to the shaft axis and including the pivot point;
- a lower bearing coupled to the shaft on a first side of the oscillation centerline;
- an upper bearing coupled to the shaft on a second side of the oscillation centerline, the second side being opposite the first side;
- an internally threaded base nut adapted to be selectively secured in position on the shaft by engaging the plurality of external threads;
- a bearing spacer moveably secured on the shaft between the upper bearing and the base nut;
- and
- a plurality of bolts biased against the based nut, wherein advancement of the plurality of bolts relative to the base nut forces the bearing spacer away from the base nut thereby applying a preload to the lower bearing and the upper bearing.
A drill head assembly, comprising:
- a shaft having a first end and an externally threaded second end;
- an oscillator assembly configured to generate an oscillating force to the shaft positioned between the first end and the second end;
- at least one bearing coupling the shaft to the oscillator assembly;
- and
- a preload assembly coupled to the shaft, the preload assembly including:
- a base nut configured to be selectively threaded in position on the externally threaded second end of the shaft, and
- a plurality of preloaders extending through the base nut,
- wherein advancement of at least one preloader of the plurality of preloaders relative to the base nut to apply a preload force on the at least one bearing.
A drilling system, comprising:
- a rotary head assembly configured to rotate a drill rod;
- and
- a sonic head assembly coupled to the rotary head, the sonic head assembly including:
- a shaft having a shaft axis defined therein, a plurality of external threads, and a slot extending axially through the plurality of external threads,
- an oscillator assembly operatively associated with the shaft, the oscillator assembly having at least one eccentrically weighted rotor configured to rotate about a pivot point, wherein an oscillation centerline is defined transverse to the shaft axis and including the pivot point,
- a lower bearing coupled to the shaft on a first side of the oscillation centerline,
- an upper bearing coupled to the shaft on a second side of the oscillation centerline, the second side being opposite the first side,
- an internally threaded base nut adapted to be selectively secured to the plurality of external threads the shaft and thereby apply a preload to the upper bearing and the lower bearing, wherein the base nut includes an opening extending there through,
- a set screw adapted to interface with the opening and engage the slot of the shaft, thereby rotationally locking the base nut relative to the shaft, and
- a plurality of preloaders biased against the base nut, the plurality of preloaders being adapted to be advanced relative to the base nut to vary the preload on the upper bearing and the lower bearing,
- wherein the sonic head assembly is configured to transmit an oscillating vibratory force to the drill rod.
Dependencies are inferred from the claim text.