| 摘要 |
<p>This invention relates to a lubrication means for a pair of splines, each spline having a pair of side faces, at least one of which will serve as a working face, where at least portions of the working faces for the pair of splines are abutting, and wherein said means comprises a conduit for providing 5 lubricating fluid supplied at or near a non-working face and/or a non-abutting portion of the working face of at least one of the pair of splines, to the abutting working face portions. An associated percussive down hole hammer is also disclosed, along with a drive sub and drill bit therefor, as well as a method for lubricating these. C~-o LOj</p> |
