CA1104552A - Floating seal for drill bits - Google Patents
Floating seal for drill bitsInfo
- Publication number
- CA1104552A CA1104552A CA328,229A CA328229A CA1104552A CA 1104552 A CA1104552 A CA 1104552A CA 328229 A CA328229 A CA 328229A CA 1104552 A CA1104552 A CA 1104552A
- Authority
- CA
- Canada
- Prior art keywords
- cutter
- bearing pin
- cone
- bit
- bearing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000007667 floating Methods 0.000 title abstract description 4
- 238000005096 rolling process Methods 0.000 claims abstract description 37
- 239000000314 lubricant Substances 0.000 claims abstract description 34
- 238000007789 sealing Methods 0.000 claims abstract description 29
- 239000003082 abrasive agent Substances 0.000 abstract description 4
- 239000011435 rock Substances 0.000 description 13
- 229910052751 metal Inorganic materials 0.000 description 10
- 239000002184 metal Substances 0.000 description 10
- 238000005520 cutting process Methods 0.000 description 9
- 229920001971 elastomer Polymers 0.000 description 9
- 239000000463 material Substances 0.000 description 8
- 238000005553 drilling Methods 0.000 description 7
- 239000000806 elastomer Substances 0.000 description 5
- 239000000919 ceramic Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 241000905957 Channa melasoma Species 0.000 description 2
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 238000005755 formation reaction Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 230000013011 mating Effects 0.000 description 2
- 230000002829 reductive effect Effects 0.000 description 2
- 230000013707 sensory perception of sound Effects 0.000 description 2
- 244000291564 Allium cepa Species 0.000 description 1
- 235000010167 Allium cepa var aggregatum Nutrition 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 244000182067 Fraxinus ornus Species 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- HXNZTJULPKRNPR-UHFFFAOYSA-N borinine Chemical compound B1=CC=CC=C1 HXNZTJULPKRNPR-UHFFFAOYSA-N 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000013536 elastomeric material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 150000002500 ions Chemical group 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000003129 oil well Substances 0.000 description 1
- 230000036316 preload Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Earth Drilling (AREA)
Abstract
FLOATING SEAL FOR DRILL BITS
Abstract of the Disclosure A rolling cone cutter earth boring bit is provided with a floating seal for sealing the bearings of the bit from the abrasive materials in the borehole and retaining lubricant within the bearing area. At least one cantilevered bearing pin extends from the arm of the bit. A cutter receiving surface is located on the arm. A first shallow annular groove is located in said cutter receiving surface. A rolling cone cutter is adapted to be rotatably mounted on the bearing pin with said rolling cone cutter having a cone mouth. A second shallow annular groove is located within said cone mouth. Bearing and cutter retaining means are located between the bearing pin and the cone cutter. A first seal unit is positioned around the bearing pin between the cutter receiving surface and the rolling cone cutter. The first seal unit includes a first annular rigid ring positioned around the bearing pin and a first resilient ring located in the first shallow annular groove between the first annular rigid ring and the cutter receiving surface. A
second seal unit is positioned around the bearing pin and located within the cone mouth. The second seal unit includes a second annular rigid ring positioned around the bearing pin within the cone mouth and a second resilient ring located in the second shallow annular groove between the second annular rigid ring and the cone mouth. The first and second seal units cooperate when the rolling cone cutter is mounted on the bearing pin so that the first and second resilient rings urge the first and second annular rigid rings into sliding contact as the cone cutter rotates about the bearing pin.
-1a-
Abstract of the Disclosure A rolling cone cutter earth boring bit is provided with a floating seal for sealing the bearings of the bit from the abrasive materials in the borehole and retaining lubricant within the bearing area. At least one cantilevered bearing pin extends from the arm of the bit. A cutter receiving surface is located on the arm. A first shallow annular groove is located in said cutter receiving surface. A rolling cone cutter is adapted to be rotatably mounted on the bearing pin with said rolling cone cutter having a cone mouth. A second shallow annular groove is located within said cone mouth. Bearing and cutter retaining means are located between the bearing pin and the cone cutter. A first seal unit is positioned around the bearing pin between the cutter receiving surface and the rolling cone cutter. The first seal unit includes a first annular rigid ring positioned around the bearing pin and a first resilient ring located in the first shallow annular groove between the first annular rigid ring and the cutter receiving surface. A
second seal unit is positioned around the bearing pin and located within the cone mouth. The second seal unit includes a second annular rigid ring positioned around the bearing pin within the cone mouth and a second resilient ring located in the second shallow annular groove between the second annular rigid ring and the cone mouth. The first and second seal units cooperate when the rolling cone cutter is mounted on the bearing pin so that the first and second resilient rings urge the first and second annular rigid rings into sliding contact as the cone cutter rotates about the bearing pin.
-1a-
Description
Background of the Invention The pre~ent invention relates to t:he art of rolling cone cutter earth boring bits and/ more particularly,. to a ralling.c.one cutter earth bor.ing bit with improved means for sealing the bearings o* the bi-t from the abrasive materials in the bo,rehole and retaining lubricant within the bearing a:rea.
A rolling cone autter earth boring bit consists of a main bit body adapted to be connected to a rotary dr.ill string.
The bit includes individual rotatable cone cutters mounted on indi~idual bearing pins extending from the main bit body. Bearing systems are provided between the cone cutters and the bearing pins ~ :
to promote rotation of the cutters and means are provided on the outer sur~ace of the cone cutters for disintegrating the earth formations as the b~t and the cutters rotate. A sufficient supply of uncontaminated lubricant shbuld be maintained proximate the beari,ng systems throughout the lifetime of the bit. Various forms of seals have been provided between the cone cutters and the bearing p~ns. upon ~h~ch. they are mounted to retain lubricant and prevent contamination; howe~ert the need for new sealing systems is as ; .
20. acute today as any t~me in the history of rock drilling. ~' A rolling cone cutter earkh boring bit must operate under very severe conditions~ and the size and geometry o:E the bit is restricted by the operating characteristics. At the same time, a ' ' longer lifeti.me and improved performance is needed from the bit.
25 In attempting ko provide an improved bit, new and improved materials -.:
have been developed for the cutting structure of the cone cutters.
They have pro~ided a longer useful lifetime for the cone cutters.
Th~s, has resulted in the bearing systems of the bit being often the first to fail during the drilling operation. Consequently, a need .
exists for new and i~proved bear~ng systems to extend the useful lifetime o~ ~he bit and to allo~ development of other elements that interact with the sealing an~ bearing systems. In attempting -to improve the bearinq systems, various seal systems have been provided to maintain the bearing area ~ree o~ harmful materials and retain lubricant. In attempting to provide new sealing systems, great care must be taken that the overall capacity o~ the bearing systems is not reduced.
In order to more ~ully appreciate the problems involved in providing new sealing systems for rolling cone earth boring biks, the follo~ing factors should be ~orne in mind. An entirely e~fective lQ system for sealing bit bearings ~especially with non-friction elements such as balls anA rollers) has, to date, eluded designers.
Relat~vely loose manu~actur~ng tolerances inherently necessary in ~;
such bearing assemblies create sealing problems that have not been satisfactorily solved. The reyuired manufacturing tolerances preclude e~ective use of the many common shaft sealing methods due to the limited ability of shaft seals to accept loose radial fits while still maintaining an effective sealing condition. Bit designers have thus limited non-frict~ion bearing sealing methods to face type seals, usually of the rubber coated belleville spring urged type since this type consumes a minimum of space. However, this rubber coated spring has been only moderately successful because the rubber sealing element is subject to rapid deterioration both through friction heatin~ and through~abrasion from exposure to the very deleterious environment encountered in oil well or blast hole drilling operations. So~e single element elastomer urged ; metal-to-metal arrangements have been tried but these have generally met ~ith poor success sl~ce one`of the mating metal faces has to he incorporated into the arm or cone of the rock bit and the necessary highly f~nis~ed l~pped sur~ces-create special problems that the 3Q rock bit manu~acturer cannot solve economically~
Thùs ~s can be~seen that, to date, face type seals have not provided the lon~ life and sealing efficiency necessary for
A rolling cone autter earth boring bit consists of a main bit body adapted to be connected to a rotary dr.ill string.
The bit includes individual rotatable cone cutters mounted on indi~idual bearing pins extending from the main bit body. Bearing systems are provided between the cone cutters and the bearing pins ~ :
to promote rotation of the cutters and means are provided on the outer sur~ace of the cone cutters for disintegrating the earth formations as the b~t and the cutters rotate. A sufficient supply of uncontaminated lubricant shbuld be maintained proximate the beari,ng systems throughout the lifetime of the bit. Various forms of seals have been provided between the cone cutters and the bearing p~ns. upon ~h~ch. they are mounted to retain lubricant and prevent contamination; howe~ert the need for new sealing systems is as ; .
20. acute today as any t~me in the history of rock drilling. ~' A rolling cone cutter earkh boring bit must operate under very severe conditions~ and the size and geometry o:E the bit is restricted by the operating characteristics. At the same time, a ' ' longer lifeti.me and improved performance is needed from the bit.
25 In attempting ko provide an improved bit, new and improved materials -.:
have been developed for the cutting structure of the cone cutters.
They have pro~ided a longer useful lifetime for the cone cutters.
Th~s, has resulted in the bearing systems of the bit being often the first to fail during the drilling operation. Consequently, a need .
exists for new and i~proved bear~ng systems to extend the useful lifetime o~ ~he bit and to allo~ development of other elements that interact with the sealing an~ bearing systems. In attempting -to improve the bearinq systems, various seal systems have been provided to maintain the bearing area ~ree o~ harmful materials and retain lubricant. In attempting to provide new sealing systems, great care must be taken that the overall capacity o~ the bearing systems is not reduced.
In order to more ~ully appreciate the problems involved in providing new sealing systems for rolling cone earth boring biks, the follo~ing factors should be ~orne in mind. An entirely e~fective lQ system for sealing bit bearings ~especially with non-friction elements such as balls anA rollers) has, to date, eluded designers.
Relat~vely loose manu~actur~ng tolerances inherently necessary in ~;
such bearing assemblies create sealing problems that have not been satisfactorily solved. The reyuired manufacturing tolerances preclude e~ective use of the many common shaft sealing methods due to the limited ability of shaft seals to accept loose radial fits while still maintaining an effective sealing condition. Bit designers have thus limited non-frict~ion bearing sealing methods to face type seals, usually of the rubber coated belleville spring urged type since this type consumes a minimum of space. However, this rubber coated spring has been only moderately successful because the rubber sealing element is subject to rapid deterioration both through friction heatin~ and through~abrasion from exposure to the very deleterious environment encountered in oil well or blast hole drilling operations. So~e single element elastomer urged ; metal-to-metal arrangements have been tried but these have generally met ~ith poor success sl~ce one`of the mating metal faces has to he incorporated into the arm or cone of the rock bit and the necessary highly f~nis~ed l~pped sur~ces-create special problems that the 3Q rock bit manu~acturer cannot solve economically~
Thùs ~s can be~seen that, to date, face type seals have not provided the lon~ life and sealing efficiency necessary for
-2~
non-frictioll hearings. A result has been that bit designers have opted to switch to high accuracy tight fitting friction type journal bearings using shaft sPals such as rubber O-rinys, and with these they have had a relatively high degree of success but only in areas where proper cool~ngr such as a circulating liquid, can he supplied to the bit e~terior environment. In blast holes where air is the circulating media, cooling around the body of the bit is not adequate to allow use of frict~on type bearings and when these sealed and lubricated friction bearing bits are used in a blast hole application~ the bit soon heats up to an into:Lerable extent causing the elastomers in the seals to fail, followed quickly by failure of the bit bearings~
Designers oE blast hole bits have continued using non-friction bearings in blast hole bit bearing assemblies because of ;~
the foregoing considerations. Since it is desirable that these bearings be ~itted with a maximum size and quantity of rolling elements to withstand the ~ery hea~y loads imposed while at the same time yielding to the hole size limitations specified by the user, a class~c designers dilemma of aaapting a maximum capacity bearing in a minimum o~ sp~ce is produced. This dilemma invariably ;
leads to compromises ~hich circum~ent many of the well known re~uire~ents for proper assembly and use of high precision non-~riction rolling element bear~ngs. Normal basic requirements, such as provis~ns ~or preload ~djustmenks are considered impractical in ~;
rock bit bearings due to space limttations. Thus the blast hole rock bit designer compromises his instinctive desire for high precision guided element bearings to the reality of his need for maximum capacity ~i.e., max~mum possib~e quantity of ball and roller elements cQns~stent w~th h~s special constraints) requiring him to accept a tolerance build-up across the bearing races of ten to twelve thousandths of an inch. This tolerance accumulation though reasonable, is still ~ar too much for effective operation of many forms o~ shaft seals.
non-frictioll hearings. A result has been that bit designers have opted to switch to high accuracy tight fitting friction type journal bearings using shaft sPals such as rubber O-rinys, and with these they have had a relatively high degree of success but only in areas where proper cool~ngr such as a circulating liquid, can he supplied to the bit e~terior environment. In blast holes where air is the circulating media, cooling around the body of the bit is not adequate to allow use of frict~on type bearings and when these sealed and lubricated friction bearing bits are used in a blast hole application~ the bit soon heats up to an into:Lerable extent causing the elastomers in the seals to fail, followed quickly by failure of the bit bearings~
Designers oE blast hole bits have continued using non-friction bearings in blast hole bit bearing assemblies because of ;~
the foregoing considerations. Since it is desirable that these bearings be ~itted with a maximum size and quantity of rolling elements to withstand the ~ery hea~y loads imposed while at the same time yielding to the hole size limitations specified by the user, a class~c designers dilemma of aaapting a maximum capacity bearing in a minimum o~ sp~ce is produced. This dilemma invariably ;
leads to compromises ~hich circum~ent many of the well known re~uire~ents for proper assembly and use of high precision non-~riction rolling element bear~ngs. Normal basic requirements, such as provis~ns ~or preload ~djustmenks are considered impractical in ~;
rock bit bearings due to space limttations. Thus the blast hole rock bit designer compromises his instinctive desire for high precision guided element bearings to the reality of his need for maximum capacity ~i.e., max~mum possib~e quantity of ball and roller elements cQns~stent w~th h~s special constraints) requiring him to accept a tolerance build-up across the bearing races of ten to twelve thousandths of an inch. This tolerance accumulation though reasonable, is still ~ar too much for effective operation of many forms o~ shaft seals.
-3- ~
: ::
~ ~r~ ~ ~ X
Description o~_Pr~or Art In U. S. Patent No. 3,761,145 to Percy W. Schumacher, Jr., patented September 25, 1973, a drill bit seal means is shown.
A drill bit including a roller cutter mounted on a greased bearing journal having a grease seal ring therearound and resilient means mounted between the seal ring and bearing journal to urge the seal ring against a sealing surface on the cutter in such a manner that the seal ring may be forced away from the cutter surface by some predetermined pressure from within the cutter but wherein the seal ~ '~
lQ ring arrangement provides a substantially positive seal from '~
pressures externally o~ the cutter to prevent detritus or other ~ ;
foreign material from en~ering into the bearing area intexiorly of the drill bit cutter is provided. Elastomeric material may be provided between the seal ring and thé cutter sealing surface.
In U~ S. Patent No. 3,656,764 to William P. Robinson, patented April 18/ 1972, a seal assembly for a drill bit is shown.
An earth boring drill ~it employing roller cutters is provided with an impxoved seal for inhibiting ingress of abrasive materials into the bearing surfaces and egress o~ lubricant. The improved 2Q seal is between an outwardly ~ac~ng re-entrant corner on the journal and an inwardly facing re-entrant corner on the cutter. The seal is made by a pair of O-rings engaging the opposed re-entrant corners and separated ~ a ~loating rigid ring having opposed bearing surfaces for seating the O rings into the corners. This seal accommodates radial, axial, and angular disp:Lacements of almost twice the magnitude that can be accommodated by a singl~ O-ring of the si~e of one of the O~ring~ wlthout signi~icantly increasing the length of journal needed for the seal.
' Descripit~on of Other Art 3Q The present invention is wi~hin the rolling cone cutter earth borin~ bit art and the'other art debcribed below is not ~4~
s~
relevant prior art; however, a review oE this art should prove helpful in understanding the present invention. In U.S. Paten-t No. 3,073,657 to R. V. Oxford, pa-tented January 15, 1963, a rotary seal is shown. In U.S~ Patent No. 3,073,~89 patented Januar~ 15, 1963, a method of producing mating sealing surfaces is shown. In U.S. Patent No. 3,216,513, patented November 9, 1965, a rotary wheel type rock cutter Eor tunnel boring and raise drilling operations is shown.
According to the present invention there is provided a rolling cone cutter earth boring hit including a bit body having at least one downwardly extending arm with the arm having a cutter receiving surface. A canti-levered bearing pin extends from the arm at the cutter receiving surface. A roller cone cutter is adapted to be rotatably mounted on the bearing pin, the roller cone cutter having a cone mouth. Bearlng and cutter retaining means are provided between the bearing pin and the cone cutter. A first seal unit is positioned around the bearing :
pin between the cutter receiving surface and the roller cone cutter, the first seal unit including a first annular rigid ring positioned around -the bearing pin and a first resilient ring located ~etween the first annular riyid ring and the cutter receiving surface. There is provided a second seal unit positioned around the bearing pin within the cone mouth, the second seal unit including a second annular rigid ring positioned around the bearing pin within the cone mouth and a second resilient ring located between the second annular rigid ring and the cone mouth. The first ~,o and second seal units cooperate when the rolling cone cutter ~ -is mounted on the bearing pin so that the first and second resilient rings urge the first and second annular rigid 5~
rings into sliding contac-t as the cone cu-tter rotates about the bearing pin, The present .invention provides a sealing system for a rolling cone cu-tter earth boring bit that acts as a barrier to the pulveri~ed cuttings and other abrasive materials in the borehole to prevent these materials ~rom , entering the beariny area of the bit and re-tains lubricant within said bearing area.
::
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:;:
-5a- ~ ':`
.,, ~"
~ `'''J,, cbr/~
.. .
In a specific embodimPent of the invention, a first shallow annular groove is loca-ted in a cu-tter receiving surface. The rolling cone cutter is aclapted to be rotatably mounted on the bearing pin with said xolling cone cutker having a cone mou-th. A second shallow annular groove is located within said cone mouth. The firs-t resilient ring is located in the first shallow annular groove between the first annular rigid ring and the cutter receiving surface. The second seal unit is positioned around the bearing pin and located within the cone mouth~ The second annular rigid ring is positioned around the bearing pin within the cone mouth and the second resilient ring located in the second shallow annular groove between the second annular rigid ~
ring and the cone mouth. An oil-flooded bearing is provided ~ ~;
with relatively large reservoir capacity and upward flow passageways that provide maximum protection against heat build-up in the bearing. In the event of excess heat the !
oil can be purged easily through a filler hole after several blast holes have been completed thereby maximizing bearing ~ ~ ;
llfe.
~ The unique seal of the present invention can be shown to have a number of important features not existing in the prior art. It is, however, to be understood that the scope of the present invention is defined by the claims at the end of this specification and the following description Qf the distinctions over the prior art is not to be inter-preted as limiting the coverage of the present invention.
The seal face is metal-to-metal, ceramic-to-metal, ceramic-to-ceramic or some other rigid minimum friction combination which is a vast improvement over the rubber-to-metal combinations heretofore usedin current state-of-the-art face seals for non-friction bearing bits. Seal faces, in addition, ~, cbr/~
: ::
~ ~r~ ~ ~ X
Description o~_Pr~or Art In U. S. Patent No. 3,761,145 to Percy W. Schumacher, Jr., patented September 25, 1973, a drill bit seal means is shown.
A drill bit including a roller cutter mounted on a greased bearing journal having a grease seal ring therearound and resilient means mounted between the seal ring and bearing journal to urge the seal ring against a sealing surface on the cutter in such a manner that the seal ring may be forced away from the cutter surface by some predetermined pressure from within the cutter but wherein the seal ~ '~
lQ ring arrangement provides a substantially positive seal from '~
pressures externally o~ the cutter to prevent detritus or other ~ ;
foreign material from en~ering into the bearing area intexiorly of the drill bit cutter is provided. Elastomeric material may be provided between the seal ring and thé cutter sealing surface.
In U~ S. Patent No. 3,656,764 to William P. Robinson, patented April 18/ 1972, a seal assembly for a drill bit is shown.
An earth boring drill ~it employing roller cutters is provided with an impxoved seal for inhibiting ingress of abrasive materials into the bearing surfaces and egress o~ lubricant. The improved 2Q seal is between an outwardly ~ac~ng re-entrant corner on the journal and an inwardly facing re-entrant corner on the cutter. The seal is made by a pair of O-rings engaging the opposed re-entrant corners and separated ~ a ~loating rigid ring having opposed bearing surfaces for seating the O rings into the corners. This seal accommodates radial, axial, and angular disp:Lacements of almost twice the magnitude that can be accommodated by a singl~ O-ring of the si~e of one of the O~ring~ wlthout signi~icantly increasing the length of journal needed for the seal.
' Descripit~on of Other Art 3Q The present invention is wi~hin the rolling cone cutter earth borin~ bit art and the'other art debcribed below is not ~4~
s~
relevant prior art; however, a review oE this art should prove helpful in understanding the present invention. In U.S. Paten-t No. 3,073,657 to R. V. Oxford, pa-tented January 15, 1963, a rotary seal is shown. In U.S~ Patent No. 3,073,~89 patented Januar~ 15, 1963, a method of producing mating sealing surfaces is shown. In U.S. Patent No. 3,216,513, patented November 9, 1965, a rotary wheel type rock cutter Eor tunnel boring and raise drilling operations is shown.
According to the present invention there is provided a rolling cone cutter earth boring hit including a bit body having at least one downwardly extending arm with the arm having a cutter receiving surface. A canti-levered bearing pin extends from the arm at the cutter receiving surface. A roller cone cutter is adapted to be rotatably mounted on the bearing pin, the roller cone cutter having a cone mouth. Bearlng and cutter retaining means are provided between the bearing pin and the cone cutter. A first seal unit is positioned around the bearing :
pin between the cutter receiving surface and the roller cone cutter, the first seal unit including a first annular rigid ring positioned around -the bearing pin and a first resilient ring located ~etween the first annular riyid ring and the cutter receiving surface. There is provided a second seal unit positioned around the bearing pin within the cone mouth, the second seal unit including a second annular rigid ring positioned around the bearing pin within the cone mouth and a second resilient ring located between the second annular rigid ring and the cone mouth. The first ~,o and second seal units cooperate when the rolling cone cutter ~ -is mounted on the bearing pin so that the first and second resilient rings urge the first and second annular rigid 5~
rings into sliding contac-t as the cone cu-tter rotates about the bearing pin, The present .invention provides a sealing system for a rolling cone cu-tter earth boring bit that acts as a barrier to the pulveri~ed cuttings and other abrasive materials in the borehole to prevent these materials ~rom , entering the beariny area of the bit and re-tains lubricant within said bearing area.
::
' ~, - " ~
:;:
-5a- ~ ':`
.,, ~"
~ `'''J,, cbr/~
.. .
In a specific embodimPent of the invention, a first shallow annular groove is loca-ted in a cu-tter receiving surface. The rolling cone cutter is aclapted to be rotatably mounted on the bearing pin with said xolling cone cutker having a cone mou-th. A second shallow annular groove is located within said cone mouth. The firs-t resilient ring is located in the first shallow annular groove between the first annular rigid ring and the cutter receiving surface. The second seal unit is positioned around the bearing pin and located within the cone mouth~ The second annular rigid ring is positioned around the bearing pin within the cone mouth and the second resilient ring located in the second shallow annular groove between the second annular rigid ~
ring and the cone mouth. An oil-flooded bearing is provided ~ ~;
with relatively large reservoir capacity and upward flow passageways that provide maximum protection against heat build-up in the bearing. In the event of excess heat the !
oil can be purged easily through a filler hole after several blast holes have been completed thereby maximizing bearing ~ ~ ;
llfe.
~ The unique seal of the present invention can be shown to have a number of important features not existing in the prior art. It is, however, to be understood that the scope of the present invention is defined by the claims at the end of this specification and the following description Qf the distinctions over the prior art is not to be inter-preted as limiting the coverage of the present invention.
The seal face is metal-to-metal, ceramic-to-metal, ceramic-to-ceramic or some other rigid minimum friction combination which is a vast improvement over the rubber-to-metal combinations heretofore usedin current state-of-the-art face seals for non-friction bearing bits. Seal faces, in addition, ~, cbr/~
4~S~2 can be ground and lapped in matched sets to a high precision finish which virtually guarantees tight effective sealing.
The elastomer urged sealing faces provide maximum adaptahility to misalignment and built-in bearing "slo-t", a quality which is essential for proper lubricant isolation in a rock bit cone that is subjected during operation to constantly ~luctuating multi-directional forces causing a high degree of "wobble" on the journal pin. The seal and bearing are designed such that there is maximum protection of the seal group from the adverse environment as encountered in usual practice in blast hole drilling. This protection is provided .
` :~
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.
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by a minimal clearance labrynthe passage~ay ou~board of the seal cluster~ Minimi~ing the seal group cross section and des.igning a special completely sealed oil-:Eilled reservoir in order to adapt a total package of an elastomer urged seal group, anti-friction bearings and a special oil~illed reservoir configuration to a rock bit bearing is a completely new approach in rotary rock bit sealing technology~ The above a.nd other features and advantages o.f the present invention will become apparent upon consideration of the follow~ng detailed descript~on of the invention when taken in conjunction with the accompan~ing drawings. -:
Brief Description of the Drawings F~gure l is an illustration, partially in section, of an earth boring bit constructed in accordance with the present invention.
Figure 2 is a side view of the arm of the bit shown in Figure l.
Detailed Descr;ption of the Invention Re~erring now to Figure 1, a sectional view of one arm~
o$ a rolling cone earth boring bit lO embodying the present invention is shown. The rolling cone cutter earth boring bit 10 :' consists o~ a main bit body 13 adapted to be connected to a rotary ~ '~
drill string. The bit 10 inclu~.es individual rotatable cone cutters mounted on individual:bearing pins extending from the main bit bod~. A sealing system acts as a barrier to the pulverized cuttings and other abrasive mater.ials in the borehole to prevent ::
these materials ~rom entering the bearing area of the bit and ~ :
retains lubricant within the bearing area. A double urged seal ~roup is provided. l~hile embody~ng weIl known features, this seal group has neVer been adapted for rock bits. Prior double floati,ng el~stomer urged'me~al-to-metal seal groups required space envelopes too large to fit the limited space available in a rock bit cone bearing~ Applicant's work has culminated in the development of a seal group to dimensions that are scaled down to fit a considerably reduced seal envelope~ T:his small seal envelope has resulted in a minimum negati~e impact on total cone bearing load capacity.
The body 13 of the bit 10 includes an upper threaded portion 12 that allows the bit 10 to be connected to the lower end of a rotary drill string (:not shown). The bit 10 also includes a central passageway 16 extending along the central axis o~ the bit lQ to allow drilling fluid to enter ~rom the upper section of the drill string ~not shown) immediately above and pass downward to the :
bottom o~ the well bore to flush cuttings and drilling debris from the well bore. A depending arm 9 extends from body 12. It i5 to be understood that the structure o~ the other arms are substantially identical to th.e arm 9 shown in Figure 1. A cutter 7 is rotatably positioned on the bearing pin 11 extending from the arm 9 and adapted to disin-tegrate the earth formations as the bit 10 is rotated. The ~
bearing pin 11 projects ~rom the cutter receiving surface of the ~ ~-arm. The cutting structure: on the surface of ~he cutter contacts and d~sintegrates: the ~ormattons in a mann~r that is well known in the art. The cutting structure ~s shown in the form of tungsten carbide inserts 8. It is to be understood that other cutting structures such as steel teeth may be used as khe cutting structure on the cone cutter 7.
. A plurality of ~earing systems are located in the bearing area bet~een the cutter~7 and the bearing pin 11. The bearing systems in the bearing area~include an outer roller bearing 14, a series of ball bearings 15, an inner friction bearing 17, and a thrust button 18. ~ passageway 4 ~s pro~ided to allow:lubricant to 3Q be transm~tted to the bearing systems. Another passageway 19 is al~o provi.ded that allows the ~alls that make up the ball b~aring ', -8~
system 15 to be inserted into position aft~r the cone cutter 7 is placed on the bearing pin 11. The series o~ ball bearin~s serves to lock the cone cutter on the bearing pin. After the balls are in place, a plug is inserted into the passageway 19 and welded th.erein. .:
A seal group l o~ the full floating double elastomer urged metal face-to-metal ~ace ~or ceramic face-to-~meta1 face or ceramic face-to-ceramic face or graphite ~o-metal or ~raphite-to-graphite being some of the possible alternati.ves) is Iocated between the ::' arm 9 and cutter 7. The seal group 1 is miniturized and adapted ~or use in a rock bit in a manner that minimizes the loss of bearing :~
capacity of the rock bit by m.inimizlng the space loss to the seal in the bearing en~elope. The seal group l uses seal parts (sealing rings) that are ground ~nd lapped in matched sets ~or very high , :~
sealing e~ectivene~s~ ~rhe seal group l includes a first seal unit positioned around the bearing pin 11 between the cutter receiving s.urface and the rollin~ cone cutter 7. The firs~ seal unit comprises :~
a ~rst~annular r~gid rin'g~22 positioned around the bearlng~pin~
and a fi,rst resilient ring 20 located in a first shallow annular : : :
;2~ ~ grooVe ~ between the ~irst annular rigid ring 22 and the cutter:
receiving sur~ace. A second seal unit is positioned around the ; ~.
bearing p~n ll with.in the cone'mouth.' The second seal unl-t comprises ~, -a second annular r~gid ring 23'positioned around the bearing pin ll ~ithin the cone mouth'and a second resilient ring 21 located in the 2;S second shalloT~ annular grooYe between the second annular rigid ring:
~:.: 23 and the cone mouth. The first~and second seal units cooperat~ ' hen the rolling cone cutter 7 i9; mounted on the bearing pin ll.
The first~and second resilient:rinys urge'the:first and second . .
annular rig~,d rings ~nto sliding contact as:the cone cutter rotates~
:3Q a~out the. ~earing pin.
An oil-~looded ~earing with relatively large reser~oir :~' capacity ~nd upward ,~lo~ passageways provides maximum protection ;
' ':
against heat build-up in the hearing. In the even-t of excess heat the oil can be purged easily through a filler hole after several blast holes have been com~leted thereby maYlmizing bearing li~e.
As best understood by reference to both Figures 1 anc~ 2, a bore 2 extends ~nto the body 12 from the internal surface o~ the bit body. The passage 4 extends ~rom the bore 2 to the bearing area.
A lubrlcant reservoir is located in the bore. Lubricant within the lubricant reservoir 2 is channeled into the passage 4 and is ' directed to the bearings. The reservoir 2 is completely or almost lQ completely filled w~th a high viscosity oil.
A reservoir filling system allows new oil to be introduced into the bearings during the li~etime of the bit. The ne~ oil w~ e introdusad at the lo~ermost portion of the bearing cluster through passage 3. This ls the critical load carrying portion. The oil will ~low upward through the bearing clearances and through passa;ge 4. The passage 4 angles upward and is located at the uppermost portion o~ the bearing cluster. This wil~l completely flush the bearin~s forcing all old oil into the reservoir 2 and ~::
ultimately out o~ the reser~oir through pressure relief val~e 5.
The structural details of an earth boring bit 10 constructed in accordance with the present inventicn having been described,,the operation o~ the bit 10 will now be considered.
The lubrication system of the bit 10 is filled with a suitable lubricant. The bit is rotated and thrust downward, thrusting the cutter 7 against the earth~or~ations. Continued rotation with the drill strin~ applying a thrust force to the bit causes the cutters to dis~ntegrate the ~ormat~ons~ and form the desired borehole. The present invention provides a seal unlt 1 in the cone mouth of the bi,t 1~ Wh~ch ~ill act as a ~arrier to the pulverized cuttings, the 3Q borehole ~luid and any other materials in the borehole. The seal unit 1 acts to prevent these materials from entering the bearing area . ~ ~
--10-- ~
through the cone mouth opening r thus providing an uncontaminated environment for the metal bearing elements and eliminating the abrasive wearing action o~ foreign materials in the bearing area.
The lubricant is retained within the bit by the seal unit 1 to assure a long li~etime ~or the bearing systems. The oil within ~ ;
the bearing systems and the reservoir may be replaced by introducing .:
new oil through passage 3. The new oil forces all old oiI out of the bit through.relie~ valve 5.
; .
The elastomer urged sealing faces provide maximum adaptahility to misalignment and built-in bearing "slo-t", a quality which is essential for proper lubricant isolation in a rock bit cone that is subjected during operation to constantly ~luctuating multi-directional forces causing a high degree of "wobble" on the journal pin. The seal and bearing are designed such that there is maximum protection of the seal group from the adverse environment as encountered in usual practice in blast hole drilling. This protection is provided .
` :~
. ' ' : ,~
. ~
~ .
.
:' ~
:. ' ~ ~ .
: ~
, -6a-~ .
~~ cbr/~
:` , ~ ~ ;
by a minimal clearance labrynthe passage~ay ou~board of the seal cluster~ Minimi~ing the seal group cross section and des.igning a special completely sealed oil-:Eilled reservoir in order to adapt a total package of an elastomer urged seal group, anti-friction bearings and a special oil~illed reservoir configuration to a rock bit bearing is a completely new approach in rotary rock bit sealing technology~ The above a.nd other features and advantages o.f the present invention will become apparent upon consideration of the follow~ng detailed descript~on of the invention when taken in conjunction with the accompan~ing drawings. -:
Brief Description of the Drawings F~gure l is an illustration, partially in section, of an earth boring bit constructed in accordance with the present invention.
Figure 2 is a side view of the arm of the bit shown in Figure l.
Detailed Descr;ption of the Invention Re~erring now to Figure 1, a sectional view of one arm~
o$ a rolling cone earth boring bit lO embodying the present invention is shown. The rolling cone cutter earth boring bit 10 :' consists o~ a main bit body 13 adapted to be connected to a rotary ~ '~
drill string. The bit 10 inclu~.es individual rotatable cone cutters mounted on individual:bearing pins extending from the main bit bod~. A sealing system acts as a barrier to the pulverized cuttings and other abrasive mater.ials in the borehole to prevent ::
these materials ~rom entering the bearing area of the bit and ~ :
retains lubricant within the bearing area. A double urged seal ~roup is provided. l~hile embody~ng weIl known features, this seal group has neVer been adapted for rock bits. Prior double floati,ng el~stomer urged'me~al-to-metal seal groups required space envelopes too large to fit the limited space available in a rock bit cone bearing~ Applicant's work has culminated in the development of a seal group to dimensions that are scaled down to fit a considerably reduced seal envelope~ T:his small seal envelope has resulted in a minimum negati~e impact on total cone bearing load capacity.
The body 13 of the bit 10 includes an upper threaded portion 12 that allows the bit 10 to be connected to the lower end of a rotary drill string (:not shown). The bit 10 also includes a central passageway 16 extending along the central axis o~ the bit lQ to allow drilling fluid to enter ~rom the upper section of the drill string ~not shown) immediately above and pass downward to the :
bottom o~ the well bore to flush cuttings and drilling debris from the well bore. A depending arm 9 extends from body 12. It i5 to be understood that the structure o~ the other arms are substantially identical to th.e arm 9 shown in Figure 1. A cutter 7 is rotatably positioned on the bearing pin 11 extending from the arm 9 and adapted to disin-tegrate the earth formations as the bit 10 is rotated. The ~
bearing pin 11 projects ~rom the cutter receiving surface of the ~ ~-arm. The cutting structure: on the surface of ~he cutter contacts and d~sintegrates: the ~ormattons in a mann~r that is well known in the art. The cutting structure ~s shown in the form of tungsten carbide inserts 8. It is to be understood that other cutting structures such as steel teeth may be used as khe cutting structure on the cone cutter 7.
. A plurality of ~earing systems are located in the bearing area bet~een the cutter~7 and the bearing pin 11. The bearing systems in the bearing area~include an outer roller bearing 14, a series of ball bearings 15, an inner friction bearing 17, and a thrust button 18. ~ passageway 4 ~s pro~ided to allow:lubricant to 3Q be transm~tted to the bearing systems. Another passageway 19 is al~o provi.ded that allows the ~alls that make up the ball b~aring ', -8~
system 15 to be inserted into position aft~r the cone cutter 7 is placed on the bearing pin 11. The series o~ ball bearin~s serves to lock the cone cutter on the bearing pin. After the balls are in place, a plug is inserted into the passageway 19 and welded th.erein. .:
A seal group l o~ the full floating double elastomer urged metal face-to-metal ~ace ~or ceramic face-to-~meta1 face or ceramic face-to-ceramic face or graphite ~o-metal or ~raphite-to-graphite being some of the possible alternati.ves) is Iocated between the ::' arm 9 and cutter 7. The seal group 1 is miniturized and adapted ~or use in a rock bit in a manner that minimizes the loss of bearing :~
capacity of the rock bit by m.inimizlng the space loss to the seal in the bearing en~elope. The seal group l uses seal parts (sealing rings) that are ground ~nd lapped in matched sets ~or very high , :~
sealing e~ectivene~s~ ~rhe seal group l includes a first seal unit positioned around the bearing pin 11 between the cutter receiving s.urface and the rollin~ cone cutter 7. The firs~ seal unit comprises :~
a ~rst~annular r~gid rin'g~22 positioned around the bearlng~pin~
and a fi,rst resilient ring 20 located in a first shallow annular : : :
;2~ ~ grooVe ~ between the ~irst annular rigid ring 22 and the cutter:
receiving sur~ace. A second seal unit is positioned around the ; ~.
bearing p~n ll with.in the cone'mouth.' The second seal unl-t comprises ~, -a second annular r~gid ring 23'positioned around the bearing pin ll ~ithin the cone mouth'and a second resilient ring 21 located in the 2;S second shalloT~ annular grooYe between the second annular rigid ring:
~:.: 23 and the cone mouth. The first~and second seal units cooperat~ ' hen the rolling cone cutter 7 i9; mounted on the bearing pin ll.
The first~and second resilient:rinys urge'the:first and second . .
annular rig~,d rings ~nto sliding contact as:the cone cutter rotates~
:3Q a~out the. ~earing pin.
An oil-~looded ~earing with relatively large reser~oir :~' capacity ~nd upward ,~lo~ passageways provides maximum protection ;
' ':
against heat build-up in the hearing. In the even-t of excess heat the oil can be purged easily through a filler hole after several blast holes have been com~leted thereby maYlmizing bearing li~e.
As best understood by reference to both Figures 1 anc~ 2, a bore 2 extends ~nto the body 12 from the internal surface o~ the bit body. The passage 4 extends ~rom the bore 2 to the bearing area.
A lubrlcant reservoir is located in the bore. Lubricant within the lubricant reservoir 2 is channeled into the passage 4 and is ' directed to the bearings. The reservoir 2 is completely or almost lQ completely filled w~th a high viscosity oil.
A reservoir filling system allows new oil to be introduced into the bearings during the li~etime of the bit. The ne~ oil w~ e introdusad at the lo~ermost portion of the bearing cluster through passage 3. This ls the critical load carrying portion. The oil will ~low upward through the bearing clearances and through passa;ge 4. The passage 4 angles upward and is located at the uppermost portion o~ the bearing cluster. This wil~l completely flush the bearin~s forcing all old oil into the reservoir 2 and ~::
ultimately out o~ the reser~oir through pressure relief val~e 5.
The structural details of an earth boring bit 10 constructed in accordance with the present inventicn having been described,,the operation o~ the bit 10 will now be considered.
The lubrication system of the bit 10 is filled with a suitable lubricant. The bit is rotated and thrust downward, thrusting the cutter 7 against the earth~or~ations. Continued rotation with the drill strin~ applying a thrust force to the bit causes the cutters to dis~ntegrate the ~ormat~ons~ and form the desired borehole. The present invention provides a seal unlt 1 in the cone mouth of the bi,t 1~ Wh~ch ~ill act as a ~arrier to the pulverized cuttings, the 3Q borehole ~luid and any other materials in the borehole. The seal unit 1 acts to prevent these materials from entering the bearing area . ~ ~
--10-- ~
through the cone mouth opening r thus providing an uncontaminated environment for the metal bearing elements and eliminating the abrasive wearing action o~ foreign materials in the bearing area.
The lubricant is retained within the bit by the seal unit 1 to assure a long li~etime ~or the bearing systems. The oil within ~ ;
the bearing systems and the reservoir may be replaced by introducing .:
new oil through passage 3. The new oil forces all old oiI out of the bit through.relie~ valve 5.
; .
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A rolling cone cutter earth boring bit, comprising:
a bit body, said bit body having at least one downwardly extending arm with said arm having a cutter receiving surface;
a cantilevered bearing pin extending from said arm at said cutter receiving surface;
a rolling cone cutter adapted to be rotatably mounted on said bearing pin ! said rolling cone cutter having a cone mouth;
bearing and cutter retaining means between said bearing pin and said cone cutter;
a first seal unit positioned around said bearing pin between said cutter receiving surface and said rolling cone cutter, said first seal unit comprising a first annular rigid ring positioned around said bearing pin and a first resilient ring located between said first annular rigid ring and said cutter receiving surface; and a second seal unit positioned around said bearing pin within said cone mouth, said second seal unit comprising a second annular rigid ring positioned around said bearing pin within said cone mouth and a second resilient ring located between said second annular rigid ring and said cone mouth, said first and second seal units cooperating when said rolling cone cutter is mounted on said bearing pin whereby said first and second resilient rings urge said first and second annular rigid rings into sliding contact as said cone cutter rotates about said bearing pin.
a bit body, said bit body having at least one downwardly extending arm with said arm having a cutter receiving surface;
a cantilevered bearing pin extending from said arm at said cutter receiving surface;
a rolling cone cutter adapted to be rotatably mounted on said bearing pin ! said rolling cone cutter having a cone mouth;
bearing and cutter retaining means between said bearing pin and said cone cutter;
a first seal unit positioned around said bearing pin between said cutter receiving surface and said rolling cone cutter, said first seal unit comprising a first annular rigid ring positioned around said bearing pin and a first resilient ring located between said first annular rigid ring and said cutter receiving surface; and a second seal unit positioned around said bearing pin within said cone mouth, said second seal unit comprising a second annular rigid ring positioned around said bearing pin within said cone mouth and a second resilient ring located between said second annular rigid ring and said cone mouth, said first and second seal units cooperating when said rolling cone cutter is mounted on said bearing pin whereby said first and second resilient rings urge said first and second annular rigid rings into sliding contact as said cone cutter rotates about said bearing pin.
2. The rolling cone cutter earth boring bit of claim 1 including a lubricant reservoir in said bit body, a lubricant cbr/MB 12 passage connecting said lubricant reservoir with said bearing and cutter retaining means, a relief valve connecting said lubricant reservoir with the outside of said bit, and a passage through said arm for introducing new lubricant into said bit.
3. A rolling cone cutter earth boring bit, comprising:
a bit body, said bit body having at least one downwardly extending arm with said arm having a cutter receiving surface;
a cantilevered bearing pin extending from said arm at said cutter receiving surface;
a first shallow annular groove in said cutter receiving surface;
a rolling cone cutter adapted to be rotatably mounted on said bearing pin, said rolling cone cutter having a cone mouth and a second shallow annular groove within said cone mouth;
bearing and cutter retaining means between said bearing pin and said cone cutter;
a first seal unit positioned around said bearing pin between said cutter receiving surface and said rolling cone cutter, said first seal unit comprising a first annular rigid ring positioned around said bearing pin and a first resilient ring located in said first shallow annular groove between said first annular rigid ring and said cutter receiving surface; and a second seal unit positioned around said bearing pin within said cone mouth, said second seal unit comprising a second annular rigid ring positioned around said bearing pin within said cone mouth and a second resilient ring located in said second cbr/MB 13 shallow annular groove between said second annular rigid ring and said cone mouth, said first and second seal units cooperating when said rolling cone cutter is mounted on said bearing pin whereby said first and second resilient rings urge said first and second annular rigid rings into sliding contact as said cone cutter rotates about said bearing pin.
a bit body, said bit body having at least one downwardly extending arm with said arm having a cutter receiving surface;
a cantilevered bearing pin extending from said arm at said cutter receiving surface;
a first shallow annular groove in said cutter receiving surface;
a rolling cone cutter adapted to be rotatably mounted on said bearing pin, said rolling cone cutter having a cone mouth and a second shallow annular groove within said cone mouth;
bearing and cutter retaining means between said bearing pin and said cone cutter;
a first seal unit positioned around said bearing pin between said cutter receiving surface and said rolling cone cutter, said first seal unit comprising a first annular rigid ring positioned around said bearing pin and a first resilient ring located in said first shallow annular groove between said first annular rigid ring and said cutter receiving surface; and a second seal unit positioned around said bearing pin within said cone mouth, said second seal unit comprising a second annular rigid ring positioned around said bearing pin within said cone mouth and a second resilient ring located in said second cbr/MB 13 shallow annular groove between said second annular rigid ring and said cone mouth, said first and second seal units cooperating when said rolling cone cutter is mounted on said bearing pin whereby said first and second resilient rings urge said first and second annular rigid rings into sliding contact as said cone cutter rotates about said bearing pin.
4. The rolling cone cutter earth boring bit of claim 3 including a lubricant reservoir in said bit body, a lubricant passage connecting said lubricant reservoir with said bearing and cutter retaining means, a relief valve connecting said lubricant reservoir with the outside of said bit, and a passage through said arm for introducing new lubricant into said bit.
5. A rolling cone cutter earth boring bit, comprising:
an annular bit body having an upper externally threaded portion and a central passage in said bit body;
at least one arm extending downwardly from said bit body and terminating in an inwardly downwardly projecting cylindrical bearing pin;
an annular groove in said arm at the root portion of said bearing pin;
a rolling cone cutter rotatably mounted on said cylindrical bearing pin and having an open ended cavity providing a cone mouth adjacent said root portion with said rolling cone cutter substantially surrounding said bearing pin;
an annular shoulder within said cone mouth adjacent to and concentric with said annular groove bearing;
cutter retaining means interposed between said bearing pin and said rolling cone cutter;
a seal assembly disposed in said aligned groove and shoulder between said bearing pin and said rolling cone cutter, said seal assembly including a first seal unit comprising a first annular rigid ring in said groove and a first resilient ring in sealing engagement between said groove and said first rigid ring, and a second seal unit comprising a second annular rigid ring positioned in said shoulder and a second resilient ring in sealing engagement between said shoulder and said second rigid ring, and, said first and second rigid rings of said seal units providing a relatively moveable sealing interface therebetween when said rolling cone cutter is mounted on said bearing pin whereby said first and second resilient rings urge said first and second annular rigid rings into sliding contact as said cone cutter rotates about said bearing pin;
a lubricant reservoir in said bit body;
a first upper lubricant flow passage connecting said lubricant reservoir and said bearing and cutter retaining means;
a relief valve connecting said lubricant reservoir with the outside of said bit;
a second lubricant flow passage extending from outside said arm to immediately adjacent said sealing interface on the lubricant side thereof and generally opposite said upper passage for introducing new lubricant into said bit; and a plug for closing said second passage whereby new oil introduced from said second passage must flow adjacent the sealing interface and across the bearings to flush the previous oil therefrom for expulsion through said relief valve.
an annular bit body having an upper externally threaded portion and a central passage in said bit body;
at least one arm extending downwardly from said bit body and terminating in an inwardly downwardly projecting cylindrical bearing pin;
an annular groove in said arm at the root portion of said bearing pin;
a rolling cone cutter rotatably mounted on said cylindrical bearing pin and having an open ended cavity providing a cone mouth adjacent said root portion with said rolling cone cutter substantially surrounding said bearing pin;
an annular shoulder within said cone mouth adjacent to and concentric with said annular groove bearing;
cutter retaining means interposed between said bearing pin and said rolling cone cutter;
a seal assembly disposed in said aligned groove and shoulder between said bearing pin and said rolling cone cutter, said seal assembly including a first seal unit comprising a first annular rigid ring in said groove and a first resilient ring in sealing engagement between said groove and said first rigid ring, and a second seal unit comprising a second annular rigid ring positioned in said shoulder and a second resilient ring in sealing engagement between said shoulder and said second rigid ring, and, said first and second rigid rings of said seal units providing a relatively moveable sealing interface therebetween when said rolling cone cutter is mounted on said bearing pin whereby said first and second resilient rings urge said first and second annular rigid rings into sliding contact as said cone cutter rotates about said bearing pin;
a lubricant reservoir in said bit body;
a first upper lubricant flow passage connecting said lubricant reservoir and said bearing and cutter retaining means;
a relief valve connecting said lubricant reservoir with the outside of said bit;
a second lubricant flow passage extending from outside said arm to immediately adjacent said sealing interface on the lubricant side thereof and generally opposite said upper passage for introducing new lubricant into said bit; and a plug for closing said second passage whereby new oil introduced from said second passage must flow adjacent the sealing interface and across the bearings to flush the previous oil therefrom for expulsion through said relief valve.
6. Structure according to claim 5 wherein said second lubricant flow passage terminates in generally the lowermost area of said sealing interface corresponding to the critical load-carrying portion of said bearing for insuring delivery of new lubricant to this area when new lubricant is introduced through the second passage.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US92086878A | 1978-06-30 | 1978-06-30 | |
| US920,868 | 1978-06-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1104552A true CA1104552A (en) | 1981-07-07 |
Family
ID=25444541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA328,229A Expired CA1104552A (en) | 1978-06-30 | 1979-05-24 | Floating seal for drill bits |
Country Status (4)
| Country | Link |
|---|---|
| AU (1) | AU525959B2 (en) |
| CA (1) | CA1104552A (en) |
| MX (1) | MX148836A (en) |
| ZA (1) | ZA792616B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5016719A (en) * | 1990-01-24 | 1991-05-21 | Western Rock Bit Company Limited | Rotary cone type rock bits |
-
1979
- 1979-05-23 AU AU47358/79A patent/AU525959B2/en not_active Ceased
- 1979-05-24 CA CA328,229A patent/CA1104552A/en not_active Expired
- 1979-05-28 ZA ZA792616A patent/ZA792616B/en unknown
- 1979-06-28 MX MX17828579A patent/MX148836A/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5016719A (en) * | 1990-01-24 | 1991-05-21 | Western Rock Bit Company Limited | Rotary cone type rock bits |
Also Published As
| Publication number | Publication date |
|---|---|
| AU4735879A (en) | 1980-01-03 |
| AU525959B2 (en) | 1982-12-09 |
| MX148836A (en) | 1983-06-24 |
| ZA792616B (en) | 1980-06-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |