Intermediate thrust elements are positioned between the cutters and the bearing pins of an earth boring bit. Each intermediate thrust element is located between a thrust surface on a bearing pin and a thrust surface on the associated cutter. The intermediate thrust elements aid stabilization of the rotating cutter, promote cutter rotation and extend the lifetime of the bit.
The bearing capacity of a rotary rock bit is increased by providing a bearing separator and sealing system which maintains the cylindrical roller bearings in proper alignment without interfering with the integrity of the seal. A spacer unit is positioned around the bearing pin of the rock bit between the cutter member and the bearing pin. The spacer unit includes an annular body with a plurality of separator elements cantilevered from said annular body extending toward the outer end of the bearing pin. The cylindrical rollers are alternately positioned between the separator elements. The annular body of the spacer unit is located in the cone mouth of the cutter member. A seal member is located in the cone mouth of the cutter member between the rock bit body and the annular body of the spacer unit.
A rolling cone cutter earth boring bit is provided with a load carrying bearing surface that can be renewed during the earth boring operation. A canister bearing element is positioned between the bearing pin and the rolling cone cutter. The rolling cone cutter rotates about the canister bearing element in a first direction during normal drilling operations. The canister bearing element has directional stops on its inside surface. These directional stops engage directional stops on the bearing pin and prevent rotation of the canister bearing element during normal drilling operations. The bearing surface can be renewed by reversing the direction of cutter rotation thereby disengaging the canister bearing element from the directional stops and allowing it to rotate in the opposite direction until a new bearing surface is in the load area. The new surface is locked in place by the directional stops or independent means and the rolling cone cutter again is rotated in the first direction for normal drilling operation.
A rolling cutter drill bit with at least one downwardly extending leg which supports a cantilevered bearing shaft thereon is disclosed. A cutter cone is rotatably mounted on the bearing shaft by radial bearing means and by axial bearing means. A radially disposed thrust washer is positioned between the journal and the cone, the washer further defining a lubricant transferring means in each radially disposed side of the thrust washer to assure adequate lubrication of the roller cone on the journal bearing.
This invention consists of a floating spindle cap disposed between a spindle pilot bearing extending from a main journal bearing and a cone bore formed by a rotary rock bit cone secured to the journal bearing. The floating spindle cap is formed from a softer material than both the spindle bearing and the cone to accommodate for slight misalignments and edge loading between the journal bearings and the cone while working in a borehole.
A rotatable cutter is mounted upon the bearing pin of a rotary rock bit. The cutter contacts and disintegrates earth formations during the drilling of an earth borehole thereby imposing a thrust load on the cutter. The thrust load consists of an out thrust load component substantially parallel to the axis of cutter rotation and a radial thrust load component substantially perpendicular to the axis of the cutter rotation. Substantially the entire out thrust load component is transmitted from the cutter through a ball bearing raceway on the interior surface of the cutter to the ball bearings and from the ball bearings to a ball bearing raceway on the bearing pin. The ball bearing raceways on the cutter and the bearing pin extend a substantial distance on either side of the axial axes of the ball bearings.
