Abstract: An invention relating to a rock drill bit assembly primarily adapted for earth boring operations, and more particularly to a rock drill bit assembly having therewithin a temperature-controlled, sealed environ being adapted for the bearing means and the lubricant disposed between the relatively rotatable parts thereof.The rock drill bit assembly includes a rock drill main body having a journal thereon with an internally confined heat exchange means therein which is selectively controlled by a remotely located control system, at least one cone which is relatively rotatably supported from the journal facial surface, a peripheral seal adapted for fully enclosing the clearance space defined between the relatively rotatable opposing facial surfaces of the journal and the cone, and bearing means and lubricant positioned in the enclosed clearance space and adapted for reducing rotational friction between the opposing facial surfaces thereof.