Rotary drill bit

摘要

An air-cooled earth-boring drill bit including a plurality of lugs. Each lug includes a pin flange. A first roller race is distal to the pin flange. A thrust flange is distal to the first roller race. At least one pin flange vent slot 71 is arranged in a surface of the pin flange opposite the first roller race. The at least one pin flange vent slot 81 opens in a direction of a load side of a bearing. At least one thrust flange vent slot 71 is arranged in a surface of the thrust flange facing the first rollers. The at least one thrust flange vent slot 81 opens in the direction of the load side of the bearing. A plurality of flow passages are arranged within the lug to supply fluid to the at least one pin flange vent slot 71 and the at least one thrust flange vent slot 81.