Patent ID: 8118118
Filing Date: 2012-02-21
Classification: E21B

Abstract:
1. A modular rotary drill head, comprising: a base for securing the modular rotary drill head to a sled assembly of a drill rig; a housing movably coupled to said base, said housing including a first portion and an opposing second portion; a plurality of motor assemblies removably secured to an exterior surface of said first portion of said housing; a drive shaft positioned at least partially within said housing, said drive shaft being secured to said housing by at least one radial bearing, at least one upper axial bearing restricting movement in a first axial direction, and at least one lower axial bearing restricting movement in a second axial direction opposite said first axial direction thereby allowing said drive shaft to withstand high axial forces; a gear wheel secured to said drive shaft; and a plurality of removable pinions securing said plurality of motor assemblies directly to said gear wheel, said plurality of removable pinions being removably secured to said second portion of said housing.