Isolated lubrication system for drill bits

An isolated lubrication system for a rotary drill bit, comprising:

• a body having at least three cutting arms, each cutting arm having a journal extending therefrom and a rotary cutter mounted on the respective journal by means of a plurality of bearings such that a clearance is defined between the rotary cutter and a base surface of the cutting arm from which the journal extends, and a body inlet, wherein the body defines:
• a body reservoir in the body to contain a fluid lubricant, the fluid lubricant being isolated from communication outside the body;
• an arm reservoir in each of the cutting arms;
• a first conduit in the body that is in communication with the body reservoir such that the fluid lubricant from the body reservoir occupies the first conduit by means of a gravitational force,
• a second conduit in the body that is in communication with the first conduit such that the fluid lubricant from the first conduit occupies the second conduit and lubricates at least one bearing of the plurality of bearings, and
• a third conduit in the body that is in communication with the second conduit and extends to an outlet provided in the journal such that the fluid lubricant from the second conduit occupies the third conduit, exits from the outlet, and lubricates the at least one bearing;
• and
• a suction conduit extending from the body inlet in the body to the body reservoir and creating a vacuum in the body reservoir, a suction seal being provided in the suction conduit isolating the body reservoir after the vacuum is created;
• a sealing system including:
• a sealing cap provided to the body reservoir in the body to isolate the body reservoir from communication outside the body in combination with the body suction seal;
• a pin inserted in the second conduit to retain the at least one bearing in position and the fluid lubricant in the second conduit,
• a seal provided between the journal and the rotary cutter in the clearance,
• a stepped passageway extending from the seal to an opening provided between the cutting arm and the rotary cutter in the clearance, wherein the stepped passageway has an “S” or “Z” shape and is defined by a combination of a continuous lip provided in each cutting arm and a continuous groove provided in the rotary cutter in the clearance, the continuous lip being accommodated in the continuous groove in the clearance;
• each cutting arm defines an arm sealing system including an arm sealing cap and an arm suction seal provided in each arm sealing cap provided to each arm reservoir and originating from the respective arm reservoir in each cutting arm to the exterior of the body to create the vacuum in each reservoir and to isolate the respective arm reservoir in each cutting arm after the vacuum is created from communication outside the body in combination with the body suction seal.

A drilling machine, comprising:

• a power source;
• a feed unit in communication with the power source;
• and
• a drill bit connected to the feed unit;
• wherein the drill bit defines:
• a body having at least three cutting arms, each cutting arm having a journal extending therefrom and a rotary cutter mounted on the respective journal by means of a plurality of bearings such that a clearance is defined between the rotary cutter and a base surface of the cutting arm from which the journal extends, and a body inlet;
• and
• an isolated lubrication system including:
• a body reservoir in the body to contain a fluid lubricant, the fluid lubricant being isolated from communication outside the body;
• an arm reservoir in each of the cutting arms;
• a plurality of conduits in the body having direct or indirect communication with the reservoirs and with respect to each other such that the plurality of conduits facilitate lubrication between the journals and the rotary cutters and to the bearings by means of at least one of a gravitational force and a centrifugal force acting on the fluid lubricant, and
• a suction conduit extending from the body inlet in the body to the body reservoir and creating a vacuum in the body reservoir, a suction seal being provided in the suction conduit isolating the body reservoir after the vacuum is created;
• a sealing system including:
• a sealing cap provided to the body reservoir to isolate the body reservoir from communication outside the body in combination with the body suction seal;
• a seal provided between the journal and the rotary cutter in the clearance,
• a stepped passageway extending from the seal to an opening provided in the clearance, wherein the stepped passageway has an “S” or “Z” shape and is defined by a combination of a continuous lip provided in each cutting arm and a continuous groove provided in the rotary cutter in the clearance, the continuous lip being accommodated in the continuous groove in the clearance;
• each cutting arm defines an arm sealing system including an arm sealing cap and an arm suction seal provided in each arm sealing cap provided to each arm reservoir and originating from the respective arm reservoir in each cutting arm to the exterior of the body to create the vacuum in each reservoir and to isolate the respective arm reservoir in each cutting arm after the vacuum is created from communication outside the body in combination with the body suction seal.