An earth boring bit has rotating cones with two lubricant passages to
increase bearing capacity and cause lubricant circulation. A lubricant
reservoir in the body supplies lubricant to passages between the cone and
bearing pin. A pressure compensator equalizes lubricant pressure to the
exterior of the bit. A first passage leads from the reservoir to the
upper side of the bearing pin. A second passage leads from the reservoir
to the bearing pin at a point from 185 degrees to 225 degrees as seen
from an inner end of the bearing pin. This point is located in a
diverging region 51d of an annular clearance surrounding the bearing pin.