Hughes Tool Company-usa

Hughes Tool Company LLC

Camco International, Inc.

Other

Schlumberger Technology Corporation

Reedhycalog, L.p.

Bruce H Burr

Eric Charles Sullivan

Jeffery Edward Daly

Edward M Galle

George E Dolezal

Kurt M Marshek

A radial lip seal for use with roller cone drill bits is at least partially collapsed and held in place when the drill bit is subjected to hydrostatic pressure in the well bore when performing drilling operations. The drill bit and seal cooperate to form at least one void intentionally established between the outer surface of a seal recess in the bit and the outer surface of the lip seal. The drill bit has a spindle and a rolling cutter positioned around the spindle. The seal recess is formed in the rolling cutter and has an outer surface to carry the lip seal.

Lip seal for roller cone drill bit

A seal arrangement useful in a rolling cutter rock drill bit includes a pair of rigid rings disposed between the leg of the bit body and the rolling cutter. The rings have opposing faces, which have opposing sealing surfaces. The sealing surfaces occupy a portion of the faces and include wear resistant material. A gap is formed between a portion of the faces, the gap allowing lubrication to flow to the sealing surfaces from the bit's bearing cavity.

Rock bit face seal having lubrication gap

The present invention is a self adjusting, volume balanced, single energizer rigid face seal for rolling cutter drill bits with floating journal bearings. Volume balancing is accomplished by utilizing a floating static seal between the rigid face seal ring and the bearing shaft. This floating static seal ring is moved axially within a annular groove by the volume pulses caused by the axial play of the cutter when in operation. At one end of the annular groove the geometry of the rigid seal ring and bearing shaft are set such that the seal assembly achieves volume balance when the bearing is running on its OD. If the bearing is running on its OD, the floating static seal will move from where ever it is in the annular groove by the volume pulses until it reaches the balance volume position.

Single energizer face seal for rocks bits with floating journal bearings

The invention provides a mechanical face seal for rotary rock bits with a novel coil spring energization system that prevents yielding of the coil springs in extreme torque conditions. Within at least one of the coil springs is a cylindrical pin designed to co-act with the spring such that the combination becomes very stiff in the radial direction as the spring extends beyond a certain amount. This prevents the high torque from yielding the springs. When the spring returns to its normal extension, the pin does not interfere with the axial compression of the spring. This combination allows the coil spring energizers of a rotary rock bit mechanical face seal to survive the occasional extreme torque event.

Rock bit face seal having anti-rotation pins

An earth boring bit having a body and a cantilevered bearing shaft extending inwardly and downwardly from the body. A rotatable cutter with an open end is assembled over the shaft, which has a journal surface formed around a longitudinal axis. The cutter has a bearing surface sized to permit assembly over the journal surface of the shaft. At the open end of the cutter bearing surface is a seal recess which includes an intersecting wall that defines an annular, generally curved corner to oppose the journal surface of the shaft. The cutter bearing surface has a curved outer region that converges from the annular corner of the seal recess into an inner region to reduce the stress the corner induces upon the journal bearing surface of the shaft, including the stress induced by cutter cocking during drilling.

Earth boring bit with convergent cutter bearing

An earth boring bit having a cantilevered bearing shaft and a compensator system to equalize the pressure of the lubricant with the hydrostatic pressure of the drilling fluid surrounding the bit. A rigid face seal assembly, positioned between the cutter and bearing shaft of the bit, moves axially in response to, and to compensate for, dynamic pressure changes in the lubricant adjacent the seal. The positioning and sizing of resilient energizer rings in relationship to the geometries of the mating grooves between the cutter and shaft and the rigid sealing rings of the face seal assembly minimize axial seal movement relative to cutter and shaft during drilling to enhance seal life. A threaded bearing lug receives an internally threaded bearing sleeve. The journal bearing surface is approximately midway between the shaft seal groove, a portion of which is on its bearing sleeve and another portion on the cutter seal groove.

Earth boring bit with two piece bearing and rigid face seal assembly

An earth boring bit having a lubrication system that includes a pressure compensator and seals to confine lubricant within the bearings between rotatable cutters and shafts, the seals being of the asymmetrical shear/compression type, each half of which having a load deflection curve resulting from components satisfying the following criteria:

Earth boring bit with shear compression seal

An earth boring bit having a cantilevered bearing shaft and a compensator system to equalize the pressure of the lubricant with the hydrostatic pressure of the drilling fluid surrounding the bit. A rigid face seal assembly, positioned between the cutter and bearing shaft of the bit, moves axially in response to, and to compensate for, dynamic pressure changes in the lubricant adjacent the seal. The positioning of the seal groove and seal assembly in relation to the bearing surface is such that rigid face seal movement is decreased relative to axial cutter movement during drilling to enhance seal life. Preferably the ratio of rigid ring movement to axial cutter movement is substantially one half to one.

Earth boring bit with improved rigid face seal assembly

An earth boring bit having a pressure compensating seal assembly which includes a resilient packing ring, a rigid backup ring and a wave spring to permit axial displacement of the resilient ring in an elongated seal groove while resisting destructive distortions of the resilient ring. The lubrication system has a lubricant volume correlated with the volume of the passages and spaces and the maximum seal displacement. A measured amount of lubricant is withdrawn from the system during assembly for subsequent compression as the bit is lowered into a liquid-filled bore hole to position the seal assembly intermediate the end walls of the seal groove.

Earth boring bit with pressure compensating bearing seal

An earth boring bit having a cantilevered bearing shaft and a compensator system to equalize the pressure of the lubricant with the hydrostatic pressure of the drilling fluid surrounding the bit. A rigid face seal assembly, positioned between the cutter and bearing shaft of the bit, moves axially in response to, and to compensate for, dynamic pressure changes in the lubricant adjacent the seal. This is accomplished by the positioning and sizing of resilient energizer rings in relationship to the geometries of the mating grooves between the cutter and shaft and the rigid sealing rings of the face seal assembly.

Earth boring bit with pressure compensating rigid face seal

Disclosed herein is an earth boring bit of otherwise conventional construction except for the bearing and cutter retention. A snap ring is used to retain the cutter, the grooves that receive the ring and the ring construction being such that the ring is forced into the retainer groove when the cone is thrust inward. The ring cannot therefor accidentally return to its assembly position to permit cutter loss. This enables the use of exclusively frictional bearings and retainer means of exceptional strength and reliability.

Earth boring drill bit with snap ring cutter retention

An abrasive wear tester wherein a segment of a relatively small diameter O-ring is held in contact with a rotating cylindrical disk. The disk is mounted to rotate about its longitudinal axes at a known rate for a specified period of time. The O-ring segment and cylinder are immersed in an abrasive fluid. The abrasive particles are pulled between the wear surfaces causing removal of the surface materials, predominantly the softer O-ring material. The O-ring specimen is cut from an O-ring and weighed prior to test. After the test the O-ring segment is again weighed and the weight of material removed by wear is calculated. These measurements indicate the wear resistance of the O-ring being tested. Service loads or pressures are simulated by means of a cable and weight system urging the O-ring against the cylindrical wear disk surface by means of a lever arm pulley arrangement or similar loading device.

Growing community of inventors

Houston, TX, United States of America

Bruce H Burr