CA1098110A - Reduction unit of drilling motor - Google Patents
Reduction unit of drilling motorInfo
- Publication number
- CA1098110A CA1098110A CA319,374A CA319374A CA1098110A CA 1098110 A CA1098110 A CA 1098110A CA 319374 A CA319374 A CA 319374A CA 1098110 A CA1098110 A CA 1098110A
- Authority
- CA
- Canada
- Prior art keywords
- reduction unit
- reduction gear
- drilling motor
- motor according
- supports
- 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
- 230000009467 reduction Effects 0.000 title claims abstract description 146
- 238000005553 drilling Methods 0.000 title claims abstract description 90
- 239000012530 fluid Substances 0.000 claims abstract description 73
- 230000000694 effects Effects 0.000 claims abstract description 10
- 238000006073 displacement reaction Methods 0.000 claims abstract description 9
- 239000000969 carrier Substances 0.000 claims abstract description 5
- 230000008878 coupling Effects 0.000 claims description 14
- 238000010168 coupling process Methods 0.000 claims description 14
- 238000005859 coupling reaction Methods 0.000 claims description 14
- 239000003381 stabilizer Substances 0.000 claims description 8
- 230000013011 mating Effects 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 230000001050 lubricating effect Effects 0.000 claims description 6
- 238000004891 communication Methods 0.000 claims description 4
- 230000006854 communication Effects 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 4
- 238000006722 reduction reaction Methods 0.000 description 109
- 239000003921 oil Substances 0.000 description 22
- 239000000314 lubricant Substances 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 210000004907 gland Anatomy 0.000 description 2
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- 241000820057 Ithone Species 0.000 description 1
- 235000018734 Sambucus australis Nutrition 0.000 description 1
- 244000180577 Sambucus australis Species 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- HDDSHPAODJUKPD-UHFFFAOYSA-N fenbendazole Chemical compound C1=C2NC(NC(=O)OC)=NC2=CC=C1SC1=CC=CC=C1 HDDSHPAODJUKPD-UHFFFAOYSA-N 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B4/00—Drives for drilling, used in the borehole
- E21B4/003—Bearing, sealing, lubricating details
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q5/00—Driving or feeding mechanisms; Control arrangements therefor
- B23Q5/02—Driving main working members
- B23Q5/04—Driving main working members rotary shafts, e.g. working-spindles
- B23Q5/12—Mechanical drives with means for varying the speed ratio
- B23Q5/16—Mechanical drives with means for varying the speed ratio infinitely-variable
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B4/00—Drives for drilling, used in the borehole
- E21B4/006—Mechanical motion converting means, e.g. reduction gearings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
- F16H37/02—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings
- F16H37/021—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings toothed gearing combined with continuous variable friction gearing
- F16H37/022—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings toothed gearing combined with continuous variable friction gearing the toothed gearing having orbital motion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H57/00—General details of gearing
- F16H57/08—General details of gearing of gearings with members having orbital motion
- F16H57/082—Planet carriers
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Geology (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Fluid Mechanics (AREA)
- Environmental & Geological Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Physics & Mathematics (AREA)
- General Details Of Gearings (AREA)
- Drilling And Boring (AREA)
- Earth Drilling (AREA)
- Retarders (AREA)
- Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
Abstract
Abstract of the Disclosure In a reduction unit of a drilling motor comprising a cas-ing, input and output shafts installed on supports, a reduction gear including sun and crown wheels, pinion carriers and planet pinions with supports located in a circular space between the wheels, an oil-filled chamber and a system of oil protection, there is provided a means eliminating the overloading of the reduction gear and a means eliminating the effect of torque fluctuations on the operation of the reduction gear while the supports of the input and output shafts installed on the ends of said shafts connected with the reduction gear are made in the form of articulated units taking axial loads and permitting angular displacements of the shafts, each of said shafts carrying a seal installed side by side with said support at the side opposite to the reduction gear, said seal being provided with a dividing space filled with a buffer fluid which protects said seal against contact with the drilling fluid.
Description
P~EI)UCTTON UN;tT O~ LI,IhG ~qO'i'OR
~ he prese~t i~vention relates to drillin~ industry and, more particularl~ to 'he reduction u~,ts of drilling motors.
Mos-t ef~ecti~le~g the prese~t invention will be employed ~or drilling deep oil and gas wells~ though it will also prove ~seful in m~.ni~ industry and in the field of construction.
q~he use of reduc-tion units in clrilling motors is not a rbol~ l l l s noveltg. One of the f rst ~xbc~ incorporated a planeta-xy reduction gear in~t~elc1 between the operating element, i.e~ tuxbine, and the supporting membe~ intended to txansmit the weight of drill pipes to the bit. q'he reductio~ gear was located in an oil-filled ch~mber. ~he chamber seals had the form of packed glands with intermediate metal rings. ~he b~.sic disadvantages of the device were the absence o~ tho mea~s fox ~educing the pressure drop in the lubricator seals and a low durability of ~aid seals under the specific working conditions of well bottom drilling. Hence, the efficiency of the reduction gear wa8 very low and the sex~ice life failed to reach 10 hours eve~ at a low power developed by o~e stage of the turbodrill.
The basic factors affecti~g the performa~ce of the reduc-tion unit in the course of drilling are ~s ~ollows.
~ o ensure efficient fu~ctioning of the rock-breaking tool it i~ necessary to transmit high power and torgue ~rom the power generating eleme~ts to the well face at a limited diameter of the drilli~g motor. ~hus, with the motox diameter of 195 mm the tor~ua applied to the bit i~ the course of drilli~g amou~ts to 300 500 ~gfm.
:
iO98i~0 Due to the an~sotropy of the drilled roC~9 the surEace irregularities o~ the wall fac~ and the toothed surface o~
the bit cu~ters, the bit is subjected to heavy axial vibrations together ~Jith the drilling motor. ~his i5 accompani-~d b~ Yluctuation~ o~ torque~ the am~litude of ~aid ~luctuation~ reaching and even 0xceedin~ t~ice the value of the above-~pecified avexage torque. I~ the last case the bit, and consequently~ the elements of the reduction gear ma~ start rotating in the revexse direction.
Operation of the d~illing motor is also accompanied b~
strong radial vibratioDs which cause bending of the basic motor parts, i.e. casings and ~hafts whose longitudinal di-mensions are considerably longer tha~ the lateral dimensions of the motor parts, this bringing about axial misalignment of the coupled motor shafts and heavy radial loads imposed on th~ir support~.
~ he process of drilling presuppofie~ the use o~ a drilling fluid containing hard abrasive particles ~hich cause rapid wear of the reduction gear. When the reduction gear is sealed in a~ oil-~illed chamber protected by seals, the seals proper become intensively worn. ~his process is a~gravated bg pulsat-so A io~s in the fluid pressure ~e that the particles containedi~ the ~luid are periodicall~ forced into the gaps between the seals.
~ he above-listed ~actors pro~e that neglect of any one of them cuts down the ~ervice li~e of the reductio~ unit; therefo~a
~ he prese~t i~vention relates to drillin~ industry and, more particularl~ to 'he reduction u~,ts of drilling motors.
Mos-t ef~ecti~le~g the prese~t invention will be employed ~or drilling deep oil and gas wells~ though it will also prove ~seful in m~.ni~ industry and in the field of construction.
q~he use of reduc-tion units in clrilling motors is not a rbol~ l l l s noveltg. One of the f rst ~xbc~ incorporated a planeta-xy reduction gear in~t~elc1 between the operating element, i.e~ tuxbine, and the supporting membe~ intended to txansmit the weight of drill pipes to the bit. q'he reductio~ gear was located in an oil-filled ch~mber. ~he chamber seals had the form of packed glands with intermediate metal rings. ~he b~.sic disadvantages of the device were the absence o~ tho mea~s fox ~educing the pressure drop in the lubricator seals and a low durability of ~aid seals under the specific working conditions of well bottom drilling. Hence, the efficiency of the reduction gear wa8 very low and the sex~ice life failed to reach 10 hours eve~ at a low power developed by o~e stage of the turbodrill.
The basic factors affecti~g the performa~ce of the reduc-tion unit in the course of drilling are ~s ~ollows.
~ o ensure efficient fu~ctioning of the rock-breaking tool it i~ necessary to transmit high power and torgue ~rom the power generating eleme~ts to the well face at a limited diameter of the drilli~g motor. ~hus, with the motox diameter of 195 mm the tor~ua applied to the bit i~ the course of drilli~g amou~ts to 300 500 ~gfm.
:
iO98i~0 Due to the an~sotropy of the drilled roC~9 the surEace irregularities o~ the wall fac~ and the toothed surface o~
the bit cu~ters, the bit is subjected to heavy axial vibrations together ~Jith the drilling motor. ~his i5 accompani-~d b~ Yluctuation~ o~ torque~ the am~litude of ~aid ~luctuation~ reaching and even 0xceedin~ t~ice the value of the above-~pecified avexage torque. I~ the last case the bit, and consequently~ the elements of the reduction gear ma~ start rotating in the revexse direction.
Operation of the d~illing motor is also accompanied b~
strong radial vibratioDs which cause bending of the basic motor parts, i.e. casings and ~hafts whose longitudinal di-mensions are considerably longer tha~ the lateral dimensions of the motor parts, this bringing about axial misalignment of the coupled motor shafts and heavy radial loads imposed on th~ir support~.
~ he process of drilling presuppofie~ the use o~ a drilling fluid containing hard abrasive particles ~hich cause rapid wear of the reduction gear. When the reduction gear is sealed in a~ oil-~illed chamber protected by seals, the seals proper become intensively worn. ~his process is a~gravated bg pulsat-so A io~s in the fluid pressure ~e that the particles containedi~ the ~luid are periodicall~ forced into the gaps between the seals.
~ he above-listed ~actors pro~e that neglect of any one of them cuts down the ~ervice li~e of the reductio~ unit; therefo~a
- 2 -.
1~)98110 provision of an efficient and durable reductlon unit of a drilling mo~or can be achieved exclusively by a comprehensive solution of the problems posed by all these factors.
At present there is known a nurnber of types of retlllc~lon units of a drilling motor.
Known in the previous art is a reduction of a drilling motor comprising a casing, input and output shafts mounted on supports, a planetary reduction gear accommodated in an oil-filled chamber provided with an oil-protec~ion system consisting of face seals which are better adapted for face-drilling conditions than the packed glands. The input shaft is coupled with the reduction gear by a splined sleeve while the output shaft is connected to the pinion carrier of the planetary reduction gear by a screw joint. The channel for the drilling fluid has the form of central holes in the reduction unit shafts.
A disadvantage of this prior art reduction unit lies in that said unit can be employed only in such drilling motors whose actuating elements have an oil-protection system of their own, for example in electrodrills, because the reduction unit has no seal on the input shaft. The output shaft seal is also not - adapted for operation in contact with hydraulic fluid so that the supporting member of the motor connected with the reduction unit output shaft must also be filled with oil which is not always warranted economically.
1~:198110 Qnother disadva~tage o~ said prior art l~eduction unit lies in the necessity ~or additional devices intended to seal of~ the cleaxa~ces b~t~leen the reduction gear d~iving and d~iven shafts sotating at different speeds, and all the splined jointr~ o~ the reduction unit shafts.
~h~ Known in the priox art is *se~dL reduction unit of a dril].ing motor comprising an input shaft and an output ~ha~t, both mounted on supports9 and a two-stage planetaxy reduction geax accommodated in an oil-filled chamber. The channel for Ç ~ v'l 1 the pas~ge of t~e d~illin~ ~liud i~ made in the form of a circular space fitted arou~d the oil-filled chamber which dispenses with the need for the seals between the driving and driv~n sha~:ts of the reduction gear stages, rotating at different speeds. The planet pinion~ of the planetary reduct-io~ ~ear are installcd rotatably on tho ~ha~ts secured in the pinion carricrs, the planet pinions of the seco~d stage being a~ I o ,~ ~ ~ s tw~ce ~se~th~n the planet pinions of the first atage.
A di~advantage of this reduction unit lies in that,like in the above-described device, its employment i~ confined to tbe drilling motors workin~ in conjunction with oil-filled mechaniams because the reduction unit is devoid of the oil--protection system of its own. The use of this reduction unit in hyd~aulic drillin~ motors is impossible.
~ nother disadvanta~e of said reduction unit lies in that its input and output sha~ts aLo mad~ integral ~ith the _4 .
.
L i ~ : -: - -`
~9~V
p~rts of the reduction unit : the input shaft carries the sun wheel at one end while the output shaft is made integral w;th the 2nd stage pinion carrier, each shaft beiny mounted on two rigi.d s~lr)ports. In this layout the parts of the unit are complicated in rnanufactuxe; moreover, in case of wear of the planetary reduction year parts i.t becomes necessary to replace hoth the input and output shafts. Moreover, the working conditi.ons of the gear drive are impaired hecause the elements of the planetary reduction gear fail to be self-adjusted so that the load is not distributed uniformly bet~een the planet pinions. When the cantilever-mounted shafts of the reduction unit are connected with the shafts of the adjacent sections, their axial misalignment imposes heavy radial loads on the supports of the input and output shafts thus ruining said sur)ports prematurely.
One more disadvantaye of the prior art reduction unit lies in that the planet pinion supports are located in their inner holes which denies the possibility of changing their load capacity because the planet pinions have but limited radial dimensions. Apart from that, doubling the length of 2nd stage planet pinions of the reduction gear fails to ensure .
equal serviceability of both reduction gear stages because the torque of the 2nd stage increase roughly proportionally to the speed ratio of the 1st stage and said ratio for the planetary transmissions used in the prior art reduction unit is always higher than two.
~9~10 The ncarest technical solution is constituted by the prior art reduction unit of a drilling engine comprising a casing ;nput and output shafts mounted on supports, a reduction gear comprising sun and crown wheels, a planet carrier and planet pir~ions with supports located in a circu]ar space between the whee]s, an oil-filled chamber and a system of oil protection collsisting of seals. The channel for the drilling fluid has the form of a circular space fitted around the oil-filled chamber on the outside.
A disadvantage of the prior art xeduction unit lies in that its input and output shafts are mounted on rigid supports installed at short distances from one another and that there are long cantilevered porticns of said shafts which imposes heavy radial loads on said supports and ruins them ultimately.
This causes play in the shafts and disturbs the tightness of the seals.
Similarly to the above-described prior art reduction unit the planet pinion supports are located inside said pinions-and there are no devices protecting the reduction gear against overloads and torque fluctuations.
Another disadvantage of the known reduction unit of a drilling motor lies in that the seals are in contact with the drilling fluid and are, therefore, rapidly worn so that the `, oil-protection system loses its tightness.
One more disadvantage of the prior art reduction unit lies in that its casing is made integral with the housing of ~j :`
~i ~o~s~o the working elements which prcvents the characteristics of the drilling motor to be adjusted with the same working e]ements by replacing a reduction unit by another one or by consecutively connecting several reduction units for changing the speed ratio of the reduction gear to suit the optimum conditiolls of drilliny in each portion of the well.
The principal object of the present invention resides in providing a reduction unit which will reduce the rotation speed and increase the torque of hydraulic drilling motors.
Another object of the invention resides in extending the service life of the reduction unit of a drilling motor.
One more object of the invention resides in raising the load capacity of the reduction unit and its serviceabi]ity under the conditions of fluctuating torque.
Moreover, an object of the invention resides in si.mplifying the oil proection system of the reduction unit.
A further object of the invention resides also in providing a reduction unit which would permit changing the motor characteristics to obtain optimum drilling conditions.
These and other objects are accomplished by providing a reduction unit of a drilling motor, comprising a casing, input and output shafts mounted on supports, a reduction gear including sun and crown wheels, pinion carriers and planet ;- pinions with supports located in a circular space between the -~ wheels, an oil-filled chamber and a system of oil protection :
~09~1~0 com~osed of seals incorporated wherein, according to the invention, is a device safeguarding the reduction unit against overloads and a tor~ue stabilizer eliminating the effect of tor~ue fluctuations on the functioning of the reduction gear and whcrei.n the supports of the input and output shafts installed on the encls thereof connected with the reduction year are made in the form of articulated units taking axial loads and permitting angular displacement of the shafts, each of said shafts being provided with a seal located side by side with said support at the end opposite to ihe reduction gear, said seal being provided with a dividing space filled with a buffer fluid which protects said seal against contact with the drilling fluid.
It is practicable that the overload safeguardshould comprise inserts accommodating the planet pinion supports installed in the slots of the pinion carrier and that part of each slot mating with the insert should have the form of a cylindrical surface whose axis is perpendicular to, and inter-sects, the longitudinal axis of the reduction gear.
It is advantageous that the surface of the insert .~ mating with the pinion carrier be barrel-shaped while the surface located at the side of the pinion should be flat.
The inserts with the pinions are arranged in groups wherein the distances between the axes of the adjacent pinions within one group are shorter than the distances of the adjacent pinions included into different groups.
, 11~981~ -In one of the embodiments of the invention the pinions are arranged at the minimum possible distances wi-thin the groups.
It is expedient that the torque stabilizer eliminating the effect of torque fluctuations on the performance of the reduction gear be made in the form of a friction s~age of the reduction gear, comprising a spring for compressing the friction elements with a predetermined force.
It is practicable that the articulated units of the input and output shafts be made in the form of spherical bearings.
It is likewise advisable that the input and output shafts be provided with additional supports connected with the casing by flexible elements. There is a version wherein the additional supports have the form of radial rubber-metal sliding~contact bearings.
It is expedient that the dividing space be limited by a seal, a tubular element connected to the casing, and a cover secured on the shaft, the tubular element with the casing forming a channel for the passage of the drilling fluid.
In one of the embodiments the dividing space has an additional seal made in the form of an elastic diaphragm, the portion of said diaphragm connected to the tubular element being '~
located at the side of the seal while its opposite portion ;~ embraces the shaft for sealing it.
It is practicable that the density of the buffer fluid ; contained in the dividing space should be higher than that of :~, o the drill;ng fluid. In one of the embodiments it is suggested to use a lubricating fluid in the function of the buffer fluid.
It is also practicable that the dividing space in the reduction unit of the drilling motor should be in hydraulic communication with the oil-filled chamber and that the latter shouJd contain a buffer fluid.
The substance of the present invention consists in that the devices for protecting the reduction gear against overloads and torque fluctuations, the supports of the input and output shafts in the form of articulated units, the arrangement of seals side by side with the supports and the provision of dividing spaces filled with a buffer fluid eliminate the adverse effect of the well-drilling conditions on the reduction unit and ensure its long service life.
The overload safeguard and the torque stabili%er allow the reduction gear to be used under dlverse drilling conditions which depend on a large variety of factors such as the bit load, the moment capacity of the bit and rock, the rate of flow of the drilling fluid through the working elements of the motor, and the dynamic conditions at the well face. At a limited diameter of the drilling motor and, as a consequence, in absence of a considerable reserve in increasing the strength of the main load-bearing elements of the reduction gear the use of the above-listed means preserves the seriveability of the reduction gear under heavy overloads and torque fluctuations. However, sufficient durability of the reduction , gear can be ensured only b~ operation in a ].ubricating fluid.
Making the supports of the input and output shafts installed at the ends of said shafts connected to the reduction gear in the form of articu],ated units which take axial loads and permit ancJu],ar displacement of the shafts eliminates the radial 1.oad$ on said supports when they are ax.i,a].ly misaligned with the shafts of the working elements and of the support assembly intended to convey the weight of the drill pipes on to the bit. This ensures ]ong operation of the supports in absence of radial and axial play. The installation of seals on the shafts side by side with the suppor~s ensures but insignificant radial vibrations of the shafts in the seals which ' remain sufficiently tight under these conditions while the arrangement of the seals on the side of the shaft supports opposite to the reduction gear enables the support to be placed into the oil-filled chamber and thus to protect it agai.nst . abrasive wear through contact with the drilling fluid. Thus, the design of the supports in the form of spherical joints and the arrangement of the seals relative to the supports according to the invention creates the best conditions for the functioning of both the seals and the supports of the input and output shafts.
The life of the seals is extended still further because each seal is provided with a dividing space filled with a buffer fluid which protects said seal from contact with the - ~981~0 drillin~ ~luid.
~ h~ location of the planet pinion supports in the inserts in~talled in the slots of the pinion carrier makes it possible to increase the size of thes~ s~pports, thereb~ raising their load c~acity. The surfaces of' th~ carri~r slots mating with the in~exts have a cylindrical shape and t~eir ~xes ax~
perpendicular to and intersect the longitudi~al axis of the reduction gear, thus ensuring self-adjustment and u~iform loading of the pinion supports in case of high torgues on the pinion c~rrier. This layout of the reduction gear overload afe~ua.rd impro~es the load distribution between the pinions aljvst~
since it ensures self ad~iu~*~e~$ of two elements bf the pla-netary tran~mission, i.e. sun wneel and planet pinions which contributes to a longer li~e of the reduction gear txain. The barr~l-shaped surface o~ the insert ensures self~-adjustment of' the planet pinion supports in ca3e of' a cextain axial mi~alignment betw~en the axis of the planet pinion and the i r lon~itudinal axis of the reduction gear ~ a radial plane.
~he flat surface o~ the insert at the planet pinion side makes it pos~ible to reduce the length of the assemblg including the planet pinion with supports and inserts and thus to increase the load capacity of the reduction gear.
~ he arrangement of the inserts with plaDet pinions in groups wherein the distances between the axes of the ad~acent pla~et pinions within one group are shorter than the distances bet~een the axes of the adjacent planet pinion~ included into - ~2 -:
1~981~0 different groups like~ise improves the load capacity o~ the reduction gear and the rigidity of the pi~ion carrier because, comparing with the uniform distribution o~ planet pinio~s in the circular space, this layout increases the moment o~ inerti a ~d the moment of resistance of the pinion carrier in its sect-io~ acro~ the slots. ~he ma~imum e~'~ect is obtained if the ad~acent pla~et pinions within the groups are installed at minimum possible axial distances.
~ he provision o~ the torque stabilizer in the form o~ a friction stage of the reduction gear comprising a spring for compressing tha friction elements with a predetermi~ed force makes it possible to prevent the transmission of pea~ tor~ues to the reduction gear elements due to momentary slipping of the ~riction elements o~ said friction stage.
~ he support~ of the input and output shafts o~ the reduction unit made i~ th~ forM o~ spherical bearings en~ure ~imultaneous tran~mission of the rotary motion of the sha~tæ and compen-satio~ for the an~ula~ displacements o~ their axes.
Du~ to tbe arrangement wherein the additional supports o~
the input and output shaft are connected with the casing through f'lexible elements it is possible to ensure the required orientation of shaft axeæ during storage, transportation and assembly o~ the drilling motors. Such supports may be made in the form of radial rubber-metal sliding-contact supports.
Owing to the ~act that the dividing space is limited by a seal~ tubular element and cover secured on the shaft and that :
'` ,, .' :
- ~0~10 the tubular elemen~ :orm~7 tegether with the casing, ~ cha~nel for the passa~e of the drilling fluid~ the bu~`fer fluid is preserved longex in the dividing space because the kine-tic e~ergy of tbe fluid flow moving along the reduction u~it is suppressed A by ~ cove~ and the fluid i~; dixected into .aid circular channel.
q'he additional seal made in t;he form of an elastic diaphra~m connected at the side of the seal to the tubular element while at the opposite side it embraces the shaft for sealing thereo~
during ~otation, rules out the mixing of the buffer and drilling ~luids.
~ he fact that the den~ity of the buffer ~luid filling the dividing ~pace is higher than that of the drilling ~luid prevents the so-called "floating" o~ the buffer fluid in the drilling fluid and rules out the contact between the fluid ; a~d the seal when the space contains the buffer fluid.
~ he lubricatin~ material used as a buf~er fluid improve~
the durability of the ~eals; in addition~ penetration of tbe buffer fluid into the oll-filled chamber does not shcrte~
the li~e of the reductio~ gear. ~his enables the dividing space to be used as a container for stand-by lubricant which makes up for the losses of the fluid from the oil-filled c~amber, thereby dispensing ~ith one of the least reliable units, i.e. lubricator. The use of the buffer fluid with lubricating propertie~ permits hydraulic communication be-tween the di~iding space and the oil-filled chamber, when the latter ~ it~
i5 filled wi~ the buffer fluid. ~his provides for maintainin~
- 14 _ .
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~9~1~0 a constant pressure in the chamber on changes in the working temperature, the hiyh density of the buffer fluid hinders the penetration of the drilling fluid into the sealed units and the design of the oil-protection system is greatly simplified.
In the reduction units of a drilliny motor realized according to the invention ~he employment of the overload safe-guard and torque stabilizer and the improvement of the oil-protection system prolong the life of the unit under difficult well-drilling conditions. The independent system of oil protection and the casing of the reduction unit provide for its effective employment with any type of the drilling motor. For the practical purposes the present invention will be most useful in the form of a set of reduction units with different speed ratios which makes it possible to obtain any characteristic of the motor with the same working tools and motor supporting unit by changing or consecutively connecting several reduction units directly in the borehole.
Now the invention will be described in detail by way of example with reference to the accompanying drawings, in which:
Fig. 1 is a schematic longitudinal section of the reduction unit of a drilling motor;
Fig. 2 shows an axial section through a planetary reduction gear;
Fig. 3 is a section taken along line III - III in Fig.
2;
Fig. 4 is a section taken along line IV - IV in Fig. 3;
Fig. 5 is a section taken along line V - V in Fig. 2;
981~
Fig. 6 is a longitudinal section of a part of the reduction unit with an embodiment of the dividing chamber;
Fig. 7 is a longitudinal section of one of the embodiments of the reduction unit.
The reduction unit of a drilling motor, according to the in~ention, comprises a hollow cylindrical casing 1 (Fig. 1) connected with adapter sleeves 2 and 3 serving to fasten the reduction unit elements in the casing 1. A reduction gear 4 consisting of sun and crown wheels, pinion carriers and planet pinions with supports is accommodated in an oil-filled chamber A
formed by a cylindrical housing 5, by an input shaft 6 with a seal 7 and an output shaft 8 with a seal 9. The reduction gear is connected with the input 6 and output 8 shafts by gear couplings 10. The articulated supports of the shafts 6 and 8 are made in the form of spherical roller bearings 11. The seals 7 and 9 are provided with dividing spaces B and C, respectively, filled with a buffer fluid which protects the seals from contact with the drilling fluid. The space B is limited by the seal 7, bushing 12, fixed immovably on the shaft 6, a tubular element 13 tightly secured to the housing 5 and located above the seal 7, and by a cover 14 installed above the tubular element 13 and secured on the shaft 6 by means of bushings 12, 15, 16 and coupling member 17 screwed on the threaded end of the shaft 6.
The dividing space C also comprises tubular elements 18 and 19 connected with the housing 5, and a cover 20 secured .
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1~9~
on the shaft 8 by bushings 21 and 22 with the aid of coupling member 23 screwed on the threaded end of the shaft 8. The buffer fluid contained in the spaces B and C is selected in order to 5atisfy the requlrement of good adhesion to metal and absence of the tendency towards formation of chemical and mechanical compourlds with the components of the drilling fluid. The buffer fluids are usually selccted to have a density higher than that of the drilling fluid and to be lubricious in operation. The channel D intended for the passage of the drilling fluid is made in the form of a circular space between the casing 1 and associated bushings 24 and 25 at one side and the housing 5 and associated tubular elements 13 and 18 at the other.
The reduction unit is installed in the drilling motor in such a way that the adapter sleeve 2 is connected to the casing of the working tools while the adapter sleeve 3, to the casing of the motor supporting unit. Correspondingly, the shaft 6 is connected by the coupling member 17 with the driving shaft of the motor with a provision for transmitting torque while the shaft 8 is connected by the coupling member 23 in the same manner with the shaft of the motor supporting unit. Such a connection of the shafts permits relative axial displacement of the couplings without applying considerable axial forces to the spherical bearings 11; at the same time these connections play the role of additional supports for the shafts 6 and 8.
During operation of the drilling motor the shaft 6 is driven from the motor driving shaft; then rotation is further transmitted by the gear coupling 10 to the drive shaft of the reduction gear wherein the rotation speed is reduced with a corresponding increase of torque. Now rotation with 1(~9~
new parameters is transmitted by the second gear coupling lO
to the output shaft 8 and further, via the coupling member 23 and the shaft of the supporting unit, to the rock-breaking tool (bit). Axial misalignment of the shafts 6 and 8 relative to thc associated shafts of the adjacent units is made up for by the angular displacements of the axes of the reduction unit shafts 6 and 8 without applying radial forces to the supports due to the use of spherical supports 11. Thanks to the fact that the seals 7 and 9 are located near the supports 11, even the maximum possible range of angular displacements of the axes of the shafts 6 and 8 their radial play in the seals is very small (up to 0.2 mm) which is permissible for normal functioning of the seals utilized in the drilling motors. The absence of axial play in the supports ll and an insignificant range of radial vibrations of the shafts 6 and 8 at the point of the seal ensure good conditions for long functioning of the seals which, in its turn, contributes to longer life of the supports ll on the condition that lubrica~t is preserved for a long time in chamber A.
2Q The dividing spaces B and C filled with buffer fluids rule out the contact of the seals 7 and 9 with the drilling fluid containing abrasive particles; besides, washing out of lubricant from the spaces by the drilling fluid is hindered due to the difference in the densities and other properties of the fluids mentioned before. The cover 14 protects the buffer fluid in the space against being washed out by the :.
8~0 velocity head of the drilling fluid by reducing its kinetic energy and directing the flow into the circular channel D.
When a suffici.ently large amount of buffer flui.d is accumulated in the space B the l,atter can a].so function as a device (lubrica-tor) intended to make up for the losses of lubricant from ~he chamber A. The leaks occur mostly in the lower seal 9 because the drilling fluid loses a part of pressure in the channel D while pressure inside the oil-fil~,ed chamber A
stays approximately constant which makes for the pressure differential on said seal at the side of the chamber A. The leaks decrease pressure in chamber A which is accompanied by a smaller pressure drop on the seal 9 and a larger pressure drop on the seal 7, said pressure drop being directed from the space B into the chamber A. Under the effect of this pressure ~rop the lubricious buffer fluid penetrates into the chamber A, compensating for the oil leaks. The buffer fluid may consist of thickened and heavy oils, consistent lubricants, plastic materials, and liquid metals and alloys. The buffer fluid must be selected so that its mixing with the lubricating material contained in the chamber A would not reduce the lubricating properties of both liquids. To replenish the reserve of lubricants in the chamber A and spaces B and C, the casing 1 has holes for valves and plugs (not shown in the drawings).
To improve orientation of the shafts 6 and 8 when the reduction units are transported in a horizontal position, also ~8~0 when they are ;nstalled in the drilling motor it is good practice to provide said shafts with special radial supports connected wi,th the casing 1 by flexible elements which reduce the radial ~oading of the supports in case of axial misalignment of the shafts being connocted. In Fig. 1 said supports are shown in the form of rubber-metal radial sliding-contact bearings 26 with bushings 27 wherein the flexible elements are formed by rubber covering of the bearing 26.
The planetary reduction gear of the unit may have different designs and speed ratios depending on the requirements of efficiency of the drilling work. A version of the reduction gear 4 is shown in Fig. 2. It comprises the stages of the planetary gear train including sun wheels 28 and 29, crown wheels 30 and 31, planet pinions 33, 33 with supports 34, and pinion carriers 35 and 36. The gear stages are interconnected by torque-transmitting couplings 37 which can be either splined or gear type. The driving shaft 38 of the transmission is connected with the input shaft 6 via the coupling member 39 and coupling 10 (Fig. 1) while the driven shaft of the reduction gear - pinion carrier 36 - is connected by the coupling 10 with the output shaft 8. The 1st friction stage of the reduction gear is made to function as a torque stabilizer, i.e,, a device eliminating the effect of torque fluctuations on the operation of the entire reduction gear. This is achieved by providing the friction stage with a spring 40 mounted on a shaft 38 and pressing the bevel sun wheels 28 against the tapered surfaces of the planet pinions 10~81~0 32 which, in turn, are pressed by the cylindrical surfaces against the crown wheel 30 connected with the reduction unit casing 1. The parameters of the spring 40 are such that the cornpression of the friction elements 28, 32, 30 ensures trans-rnission of a maxiltlum torque required for normal operation of the rock-breaking tool. When this torque starts fluctuating and l~s upsurges may ruin the reduction year elements, the friction elements of -the stage slip momentarily thus reducing the torque upsurge.
The 2nd toothed stage of the reduction gear incorporates an overload safeguard. It includes inserts 41 (Figs. 3,4) with the supports 34 of the planet pinions 33 which are installed in the slots E of the pinion carrier 36. The portion El of each slot E mating with the insert 41 has the form of a cylindrical surface whose axis is perpendicular to the longitudinal axis of the reduction gear (coinciding with the axis of the sun wheel 29) and intersects it. The surface F of the insert 41 mating with the cylindrical surface of the slot E is barrel-shaped (Fig. 4).
The surface G of the insert 41 (Fig. 3) facing the planet pinion 33 is flat. The planetpinions 33 with supports 34 and inserts 41 are located in the circular space between the sun wheel 29 ana the crown wheel 31 irregularly, in groups (Fig. 5) so that the distances between ~he axes of the adjacent planet pinions 33a and 33b within one group are shorter than the distances between the ~981~0 axes of the adjacent planet pinions 33b and 33c included in-to difFerent groups. Accordingly, the cross sectional aréas and thc moments of resistance of the pinion carrier elements 36a and 36b ~re different too.
All the above-mentioned d;stinguishing feal-ures of the toothed stage of the reduction gear are aimed at raising the load capacity of the wearest reduction gear elements such as supports 34, planet pinions 33 and pinion carrier 36. Thus, their load capacity rises sufficiently for transmitting the torque ensuring normal functioning of the drilling bit. When torque is transmitted via the reduction gear 4, its pinion carrier 36 is twisted relative to the longitudinal axis, the carrier elements 36a and 36b (Fig. 5) bend with respect to axes X - X and Y - Y which is accompanied by turning of the shafts of the planet pinions 33 (Fig. 3) through a certain angle.
The arrangement of the reduction gear 4 in accordance with the present invention raises the total moment of resistance of the carrier elements 36a and 36b in comparison with the reduction gear whose planet pinions are spaced regularly and uniformly in the circular spacè. The maximum effect is achieved when the planet pinions 33a and 33b are contiguous to each other (Fig. 5), i.e., when the axis-to-axis distances of the planet pinions 33a and 33b are minimum and meet all the requirements of assembling the planetary transmission. The stresses in said elements of the pinion carrier are reduced still more because a considerable radius R (Fig. 3) of the cylindrical surface practically excludes stress 1(~98~0 concentrations at the junctions between the longitudinal 36a and transverse 36c elements of the pinion carrier. The flat shape of ~he surfaces G makes it possible to reduce the total Lenyth of the s]ot E 2 which contributes to higher strength and stiffness of the pinion carrier. At the same time, installation of the planet pinion supports 34 in the inserts 41 permits increasing their diameters and longitudinal loading as compared with the versions in which the supports are located inside the planet pinions. The operating conditions of the supports 34 are made still better due to the barrel-like shape of the insert 41 which permits the supports 34 to be self-adjusted if the shaft of the planet pinions 33 is mis-aligned in two mutually perpendicular planes.
A version of the dividing space B (Fig. 6) incorporates an auxiliary seal in the form of an elastic diaphraym 42.
One side of the diaphragm 42 is reinforced by metal rings 43 which allows the diaphragm 42 to be press-fitted into the tubular element 13. At the other side the diaphragm fits around the bushing 12 secured on the shaft 6 with an interference of 5 - 7 mm for sealing said bushing but permitting the shaft 6 to rotate together with said bushing 12. This auxiliary seal divides the space B into two parts sl and B2. The space Bl accommodates a lubricating buffer fluid while the buffer fluid in the space B2 is gradually substituted by the drilling fluid.
As the fluid gradually escapes from ~9~ 0 the chamber A the lubricant is replenished from the space Bl.
An advantage of this version lies in a longer preservation of the buffer f]uid in the space s.
The version of the reduction unit of a drilling motor (J~'ig. 7) diffcrs from the basic version (Fig. 1) in that the dividing space B communicatcs hydraulically through channel L with the oil-filled chamber A which accommodates the reduction gear 4 and supports 11 : the chamber A, like the chamber B, is filled with a lubricious buffer fluid. In such an arrange-ment the pressure of the drilling fluid is conveyed from thespace B into the chamber A through channel L. When the fluid volume changes in the chamber A due to thermal variations and the fluid flows back and forth through channel L, pressure in said cham~er remains unchanged so that the seal 7 is practically free from the effect of pressure drop. Its functions consist only in preventing the settling solid particles from entering the chamber A when the fluid located in the upper part of the space B above the buffer fluid is not cleaned sufficiently well. Therefore, the design of the seal 7 is simpler than it 2C is in the basic version (Fig. 1). For example it has the form of an edge-type labyrinth gate. The reduction unit of a drilling motor according to this layout (Fig. 7~ is extremely simple, sufficiently reliable and durable.
The use of the above-described technical solutions has made it possible to work out a simple and dependable design ~981~0 of the EedUCtion l~it of a drilling motor ~hich allows-e~icient drilling of wells with variou~ type~ o~ drilling motors, practically at any depth attai~able today with the c:urrent hydraulic eguipment o~ the drilling rigs. ~e self-~suf~iciency o~ the unit and its oil protect:ion system permit its use in the form of a.set of several reduction unit~
ensuriDg a series of speed ratios capable o~ providing a wide range of performance characteristics required by diverse drilling conditions without changing the ~orking elements and motor supporting units. Said units can be ~urnished to the drilling rig in a set while the re~uired characteristic o~
the motor can be determined directly at the borehole by replac-ing or consecutivelg combining several rednction units.
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1~)98110 provision of an efficient and durable reductlon unit of a drilling mo~or can be achieved exclusively by a comprehensive solution of the problems posed by all these factors.
At present there is known a nurnber of types of retlllc~lon units of a drilling motor.
Known in the previous art is a reduction of a drilling motor comprising a casing, input and output shafts mounted on supports, a planetary reduction gear accommodated in an oil-filled chamber provided with an oil-protec~ion system consisting of face seals which are better adapted for face-drilling conditions than the packed glands. The input shaft is coupled with the reduction gear by a splined sleeve while the output shaft is connected to the pinion carrier of the planetary reduction gear by a screw joint. The channel for the drilling fluid has the form of central holes in the reduction unit shafts.
A disadvantage of this prior art reduction unit lies in that said unit can be employed only in such drilling motors whose actuating elements have an oil-protection system of their own, for example in electrodrills, because the reduction unit has no seal on the input shaft. The output shaft seal is also not - adapted for operation in contact with hydraulic fluid so that the supporting member of the motor connected with the reduction unit output shaft must also be filled with oil which is not always warranted economically.
1~:198110 Qnother disadva~tage o~ said prior art l~eduction unit lies in the necessity ~or additional devices intended to seal of~ the cleaxa~ces b~t~leen the reduction gear d~iving and d~iven shafts sotating at different speeds, and all the splined jointr~ o~ the reduction unit shafts.
~h~ Known in the priox art is *se~dL reduction unit of a dril].ing motor comprising an input shaft and an output ~ha~t, both mounted on supports9 and a two-stage planetaxy reduction geax accommodated in an oil-filled chamber. The channel for Ç ~ v'l 1 the pas~ge of t~e d~illin~ ~liud i~ made in the form of a circular space fitted arou~d the oil-filled chamber which dispenses with the need for the seals between the driving and driv~n sha~:ts of the reduction gear stages, rotating at different speeds. The planet pinion~ of the planetary reduct-io~ ~ear are installcd rotatably on tho ~ha~ts secured in the pinion carricrs, the planet pinions of the seco~d stage being a~ I o ,~ ~ ~ s tw~ce ~se~th~n the planet pinions of the first atage.
A di~advantage of this reduction unit lies in that,like in the above-described device, its employment i~ confined to tbe drilling motors workin~ in conjunction with oil-filled mechaniams because the reduction unit is devoid of the oil--protection system of its own. The use of this reduction unit in hyd~aulic drillin~ motors is impossible.
~ nother disadvanta~e of said reduction unit lies in that its input and output sha~ts aLo mad~ integral ~ith the _4 .
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L i ~ : -: - -`
~9~V
p~rts of the reduction unit : the input shaft carries the sun wheel at one end while the output shaft is made integral w;th the 2nd stage pinion carrier, each shaft beiny mounted on two rigi.d s~lr)ports. In this layout the parts of the unit are complicated in rnanufactuxe; moreover, in case of wear of the planetary reduction year parts i.t becomes necessary to replace hoth the input and output shafts. Moreover, the working conditi.ons of the gear drive are impaired hecause the elements of the planetary reduction gear fail to be self-adjusted so that the load is not distributed uniformly bet~een the planet pinions. When the cantilever-mounted shafts of the reduction unit are connected with the shafts of the adjacent sections, their axial misalignment imposes heavy radial loads on the supports of the input and output shafts thus ruining said sur)ports prematurely.
One more disadvantaye of the prior art reduction unit lies in that the planet pinion supports are located in their inner holes which denies the possibility of changing their load capacity because the planet pinions have but limited radial dimensions. Apart from that, doubling the length of 2nd stage planet pinions of the reduction gear fails to ensure .
equal serviceability of both reduction gear stages because the torque of the 2nd stage increase roughly proportionally to the speed ratio of the 1st stage and said ratio for the planetary transmissions used in the prior art reduction unit is always higher than two.
~9~10 The ncarest technical solution is constituted by the prior art reduction unit of a drilling engine comprising a casing ;nput and output shafts mounted on supports, a reduction gear comprising sun and crown wheels, a planet carrier and planet pir~ions with supports located in a circu]ar space between the whee]s, an oil-filled chamber and a system of oil protection collsisting of seals. The channel for the drilling fluid has the form of a circular space fitted around the oil-filled chamber on the outside.
A disadvantage of the prior art xeduction unit lies in that its input and output shafts are mounted on rigid supports installed at short distances from one another and that there are long cantilevered porticns of said shafts which imposes heavy radial loads on said supports and ruins them ultimately.
This causes play in the shafts and disturbs the tightness of the seals.
Similarly to the above-described prior art reduction unit the planet pinion supports are located inside said pinions-and there are no devices protecting the reduction gear against overloads and torque fluctuations.
Another disadvantage of the known reduction unit of a drilling motor lies in that the seals are in contact with the drilling fluid and are, therefore, rapidly worn so that the `, oil-protection system loses its tightness.
One more disadvantage of the prior art reduction unit lies in that its casing is made integral with the housing of ~j :`
~i ~o~s~o the working elements which prcvents the characteristics of the drilling motor to be adjusted with the same working e]ements by replacing a reduction unit by another one or by consecutively connecting several reduction units for changing the speed ratio of the reduction gear to suit the optimum conditiolls of drilliny in each portion of the well.
The principal object of the present invention resides in providing a reduction unit which will reduce the rotation speed and increase the torque of hydraulic drilling motors.
Another object of the invention resides in extending the service life of the reduction unit of a drilling motor.
One more object of the invention resides in raising the load capacity of the reduction unit and its serviceabi]ity under the conditions of fluctuating torque.
Moreover, an object of the invention resides in si.mplifying the oil proection system of the reduction unit.
A further object of the invention resides also in providing a reduction unit which would permit changing the motor characteristics to obtain optimum drilling conditions.
These and other objects are accomplished by providing a reduction unit of a drilling motor, comprising a casing, input and output shafts mounted on supports, a reduction gear including sun and crown wheels, pinion carriers and planet ;- pinions with supports located in a circular space between the -~ wheels, an oil-filled chamber and a system of oil protection :
~09~1~0 com~osed of seals incorporated wherein, according to the invention, is a device safeguarding the reduction unit against overloads and a tor~ue stabilizer eliminating the effect of tor~ue fluctuations on the functioning of the reduction gear and whcrei.n the supports of the input and output shafts installed on the encls thereof connected with the reduction year are made in the form of articulated units taking axial loads and permitting angular displacement of the shafts, each of said shafts being provided with a seal located side by side with said support at the end opposite to ihe reduction gear, said seal being provided with a dividing space filled with a buffer fluid which protects said seal against contact with the drilling fluid.
It is practicable that the overload safeguardshould comprise inserts accommodating the planet pinion supports installed in the slots of the pinion carrier and that part of each slot mating with the insert should have the form of a cylindrical surface whose axis is perpendicular to, and inter-sects, the longitudinal axis of the reduction gear.
It is advantageous that the surface of the insert .~ mating with the pinion carrier be barrel-shaped while the surface located at the side of the pinion should be flat.
The inserts with the pinions are arranged in groups wherein the distances between the axes of the adjacent pinions within one group are shorter than the distances of the adjacent pinions included into different groups.
, 11~981~ -In one of the embodiments of the invention the pinions are arranged at the minimum possible distances wi-thin the groups.
It is expedient that the torque stabilizer eliminating the effect of torque fluctuations on the performance of the reduction gear be made in the form of a friction s~age of the reduction gear, comprising a spring for compressing the friction elements with a predetermined force.
It is practicable that the articulated units of the input and output shafts be made in the form of spherical bearings.
It is likewise advisable that the input and output shafts be provided with additional supports connected with the casing by flexible elements. There is a version wherein the additional supports have the form of radial rubber-metal sliding~contact bearings.
It is expedient that the dividing space be limited by a seal, a tubular element connected to the casing, and a cover secured on the shaft, the tubular element with the casing forming a channel for the passage of the drilling fluid.
In one of the embodiments the dividing space has an additional seal made in the form of an elastic diaphragm, the portion of said diaphragm connected to the tubular element being '~
located at the side of the seal while its opposite portion ;~ embraces the shaft for sealing it.
It is practicable that the density of the buffer fluid ; contained in the dividing space should be higher than that of :~, o the drill;ng fluid. In one of the embodiments it is suggested to use a lubricating fluid in the function of the buffer fluid.
It is also practicable that the dividing space in the reduction unit of the drilling motor should be in hydraulic communication with the oil-filled chamber and that the latter shouJd contain a buffer fluid.
The substance of the present invention consists in that the devices for protecting the reduction gear against overloads and torque fluctuations, the supports of the input and output shafts in the form of articulated units, the arrangement of seals side by side with the supports and the provision of dividing spaces filled with a buffer fluid eliminate the adverse effect of the well-drilling conditions on the reduction unit and ensure its long service life.
The overload safeguard and the torque stabili%er allow the reduction gear to be used under dlverse drilling conditions which depend on a large variety of factors such as the bit load, the moment capacity of the bit and rock, the rate of flow of the drilling fluid through the working elements of the motor, and the dynamic conditions at the well face. At a limited diameter of the drilling motor and, as a consequence, in absence of a considerable reserve in increasing the strength of the main load-bearing elements of the reduction gear the use of the above-listed means preserves the seriveability of the reduction gear under heavy overloads and torque fluctuations. However, sufficient durability of the reduction , gear can be ensured only b~ operation in a ].ubricating fluid.
Making the supports of the input and output shafts installed at the ends of said shafts connected to the reduction gear in the form of articu],ated units which take axial loads and permit ancJu],ar displacement of the shafts eliminates the radial 1.oad$ on said supports when they are ax.i,a].ly misaligned with the shafts of the working elements and of the support assembly intended to convey the weight of the drill pipes on to the bit. This ensures ]ong operation of the supports in absence of radial and axial play. The installation of seals on the shafts side by side with the suppor~s ensures but insignificant radial vibrations of the shafts in the seals which ' remain sufficiently tight under these conditions while the arrangement of the seals on the side of the shaft supports opposite to the reduction gear enables the support to be placed into the oil-filled chamber and thus to protect it agai.nst . abrasive wear through contact with the drilling fluid. Thus, the design of the supports in the form of spherical joints and the arrangement of the seals relative to the supports according to the invention creates the best conditions for the functioning of both the seals and the supports of the input and output shafts.
The life of the seals is extended still further because each seal is provided with a dividing space filled with a buffer fluid which protects said seal from contact with the - ~981~0 drillin~ ~luid.
~ h~ location of the planet pinion supports in the inserts in~talled in the slots of the pinion carrier makes it possible to increase the size of thes~ s~pports, thereb~ raising their load c~acity. The surfaces of' th~ carri~r slots mating with the in~exts have a cylindrical shape and t~eir ~xes ax~
perpendicular to and intersect the longitudi~al axis of the reduction gear, thus ensuring self-adjustment and u~iform loading of the pinion supports in case of high torgues on the pinion c~rrier. This layout of the reduction gear overload afe~ua.rd impro~es the load distribution between the pinions aljvst~
since it ensures self ad~iu~*~e~$ of two elements bf the pla-netary tran~mission, i.e. sun wneel and planet pinions which contributes to a longer li~e of the reduction gear txain. The barr~l-shaped surface o~ the insert ensures self~-adjustment of' the planet pinion supports in ca3e of' a cextain axial mi~alignment betw~en the axis of the planet pinion and the i r lon~itudinal axis of the reduction gear ~ a radial plane.
~he flat surface o~ the insert at the planet pinion side makes it pos~ible to reduce the length of the assemblg including the planet pinion with supports and inserts and thus to increase the load capacity of the reduction gear.
~ he arrangement of the inserts with plaDet pinions in groups wherein the distances between the axes of the ad~acent pla~et pinions within one group are shorter than the distances bet~een the axes of the adjacent planet pinion~ included into - ~2 -:
1~981~0 different groups like~ise improves the load capacity o~ the reduction gear and the rigidity of the pi~ion carrier because, comparing with the uniform distribution o~ planet pinio~s in the circular space, this layout increases the moment o~ inerti a ~d the moment of resistance of the pinion carrier in its sect-io~ acro~ the slots. ~he ma~imum e~'~ect is obtained if the ad~acent pla~et pinions within the groups are installed at minimum possible axial distances.
~ he provision o~ the torque stabilizer in the form o~ a friction stage of the reduction gear comprising a spring for compressing tha friction elements with a predetermi~ed force makes it possible to prevent the transmission of pea~ tor~ues to the reduction gear elements due to momentary slipping of the ~riction elements o~ said friction stage.
~ he support~ of the input and output shafts o~ the reduction unit made i~ th~ forM o~ spherical bearings en~ure ~imultaneous tran~mission of the rotary motion of the sha~tæ and compen-satio~ for the an~ula~ displacements o~ their axes.
Du~ to tbe arrangement wherein the additional supports o~
the input and output shaft are connected with the casing through f'lexible elements it is possible to ensure the required orientation of shaft axeæ during storage, transportation and assembly o~ the drilling motors. Such supports may be made in the form of radial rubber-metal sliding-contact supports.
Owing to the ~act that the dividing space is limited by a seal~ tubular element and cover secured on the shaft and that :
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- ~0~10 the tubular elemen~ :orm~7 tegether with the casing, ~ cha~nel for the passa~e of the drilling fluid~ the bu~`fer fluid is preserved longex in the dividing space because the kine-tic e~ergy of tbe fluid flow moving along the reduction u~it is suppressed A by ~ cove~ and the fluid i~; dixected into .aid circular channel.
q'he additional seal made in t;he form of an elastic diaphra~m connected at the side of the seal to the tubular element while at the opposite side it embraces the shaft for sealing thereo~
during ~otation, rules out the mixing of the buffer and drilling ~luids.
~ he fact that the den~ity of the buffer ~luid filling the dividing ~pace is higher than that of the drilling ~luid prevents the so-called "floating" o~ the buffer fluid in the drilling fluid and rules out the contact between the fluid ; a~d the seal when the space contains the buffer fluid.
~ he lubricatin~ material used as a buf~er fluid improve~
the durability of the ~eals; in addition~ penetration of tbe buffer fluid into the oll-filled chamber does not shcrte~
the li~e of the reductio~ gear. ~his enables the dividing space to be used as a container for stand-by lubricant which makes up for the losses of the fluid from the oil-filled c~amber, thereby dispensing ~ith one of the least reliable units, i.e. lubricator. The use of the buffer fluid with lubricating propertie~ permits hydraulic communication be-tween the di~iding space and the oil-filled chamber, when the latter ~ it~
i5 filled wi~ the buffer fluid. ~his provides for maintainin~
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~9~1~0 a constant pressure in the chamber on changes in the working temperature, the hiyh density of the buffer fluid hinders the penetration of the drilling fluid into the sealed units and the design of the oil-protection system is greatly simplified.
In the reduction units of a drilliny motor realized according to the invention ~he employment of the overload safe-guard and torque stabilizer and the improvement of the oil-protection system prolong the life of the unit under difficult well-drilling conditions. The independent system of oil protection and the casing of the reduction unit provide for its effective employment with any type of the drilling motor. For the practical purposes the present invention will be most useful in the form of a set of reduction units with different speed ratios which makes it possible to obtain any characteristic of the motor with the same working tools and motor supporting unit by changing or consecutively connecting several reduction units directly in the borehole.
Now the invention will be described in detail by way of example with reference to the accompanying drawings, in which:
Fig. 1 is a schematic longitudinal section of the reduction unit of a drilling motor;
Fig. 2 shows an axial section through a planetary reduction gear;
Fig. 3 is a section taken along line III - III in Fig.
2;
Fig. 4 is a section taken along line IV - IV in Fig. 3;
Fig. 5 is a section taken along line V - V in Fig. 2;
981~
Fig. 6 is a longitudinal section of a part of the reduction unit with an embodiment of the dividing chamber;
Fig. 7 is a longitudinal section of one of the embodiments of the reduction unit.
The reduction unit of a drilling motor, according to the in~ention, comprises a hollow cylindrical casing 1 (Fig. 1) connected with adapter sleeves 2 and 3 serving to fasten the reduction unit elements in the casing 1. A reduction gear 4 consisting of sun and crown wheels, pinion carriers and planet pinions with supports is accommodated in an oil-filled chamber A
formed by a cylindrical housing 5, by an input shaft 6 with a seal 7 and an output shaft 8 with a seal 9. The reduction gear is connected with the input 6 and output 8 shafts by gear couplings 10. The articulated supports of the shafts 6 and 8 are made in the form of spherical roller bearings 11. The seals 7 and 9 are provided with dividing spaces B and C, respectively, filled with a buffer fluid which protects the seals from contact with the drilling fluid. The space B is limited by the seal 7, bushing 12, fixed immovably on the shaft 6, a tubular element 13 tightly secured to the housing 5 and located above the seal 7, and by a cover 14 installed above the tubular element 13 and secured on the shaft 6 by means of bushings 12, 15, 16 and coupling member 17 screwed on the threaded end of the shaft 6.
The dividing space C also comprises tubular elements 18 and 19 connected with the housing 5, and a cover 20 secured .
.
1~9~
on the shaft 8 by bushings 21 and 22 with the aid of coupling member 23 screwed on the threaded end of the shaft 8. The buffer fluid contained in the spaces B and C is selected in order to 5atisfy the requlrement of good adhesion to metal and absence of the tendency towards formation of chemical and mechanical compourlds with the components of the drilling fluid. The buffer fluids are usually selccted to have a density higher than that of the drilling fluid and to be lubricious in operation. The channel D intended for the passage of the drilling fluid is made in the form of a circular space between the casing 1 and associated bushings 24 and 25 at one side and the housing 5 and associated tubular elements 13 and 18 at the other.
The reduction unit is installed in the drilling motor in such a way that the adapter sleeve 2 is connected to the casing of the working tools while the adapter sleeve 3, to the casing of the motor supporting unit. Correspondingly, the shaft 6 is connected by the coupling member 17 with the driving shaft of the motor with a provision for transmitting torque while the shaft 8 is connected by the coupling member 23 in the same manner with the shaft of the motor supporting unit. Such a connection of the shafts permits relative axial displacement of the couplings without applying considerable axial forces to the spherical bearings 11; at the same time these connections play the role of additional supports for the shafts 6 and 8.
During operation of the drilling motor the shaft 6 is driven from the motor driving shaft; then rotation is further transmitted by the gear coupling 10 to the drive shaft of the reduction gear wherein the rotation speed is reduced with a corresponding increase of torque. Now rotation with 1(~9~
new parameters is transmitted by the second gear coupling lO
to the output shaft 8 and further, via the coupling member 23 and the shaft of the supporting unit, to the rock-breaking tool (bit). Axial misalignment of the shafts 6 and 8 relative to thc associated shafts of the adjacent units is made up for by the angular displacements of the axes of the reduction unit shafts 6 and 8 without applying radial forces to the supports due to the use of spherical supports 11. Thanks to the fact that the seals 7 and 9 are located near the supports 11, even the maximum possible range of angular displacements of the axes of the shafts 6 and 8 their radial play in the seals is very small (up to 0.2 mm) which is permissible for normal functioning of the seals utilized in the drilling motors. The absence of axial play in the supports ll and an insignificant range of radial vibrations of the shafts 6 and 8 at the point of the seal ensure good conditions for long functioning of the seals which, in its turn, contributes to longer life of the supports ll on the condition that lubrica~t is preserved for a long time in chamber A.
2Q The dividing spaces B and C filled with buffer fluids rule out the contact of the seals 7 and 9 with the drilling fluid containing abrasive particles; besides, washing out of lubricant from the spaces by the drilling fluid is hindered due to the difference in the densities and other properties of the fluids mentioned before. The cover 14 protects the buffer fluid in the space against being washed out by the :.
8~0 velocity head of the drilling fluid by reducing its kinetic energy and directing the flow into the circular channel D.
When a suffici.ently large amount of buffer flui.d is accumulated in the space B the l,atter can a].so function as a device (lubrica-tor) intended to make up for the losses of lubricant from ~he chamber A. The leaks occur mostly in the lower seal 9 because the drilling fluid loses a part of pressure in the channel D while pressure inside the oil-fil~,ed chamber A
stays approximately constant which makes for the pressure differential on said seal at the side of the chamber A. The leaks decrease pressure in chamber A which is accompanied by a smaller pressure drop on the seal 9 and a larger pressure drop on the seal 7, said pressure drop being directed from the space B into the chamber A. Under the effect of this pressure ~rop the lubricious buffer fluid penetrates into the chamber A, compensating for the oil leaks. The buffer fluid may consist of thickened and heavy oils, consistent lubricants, plastic materials, and liquid metals and alloys. The buffer fluid must be selected so that its mixing with the lubricating material contained in the chamber A would not reduce the lubricating properties of both liquids. To replenish the reserve of lubricants in the chamber A and spaces B and C, the casing 1 has holes for valves and plugs (not shown in the drawings).
To improve orientation of the shafts 6 and 8 when the reduction units are transported in a horizontal position, also ~8~0 when they are ;nstalled in the drilling motor it is good practice to provide said shafts with special radial supports connected wi,th the casing 1 by flexible elements which reduce the radial ~oading of the supports in case of axial misalignment of the shafts being connocted. In Fig. 1 said supports are shown in the form of rubber-metal radial sliding-contact bearings 26 with bushings 27 wherein the flexible elements are formed by rubber covering of the bearing 26.
The planetary reduction gear of the unit may have different designs and speed ratios depending on the requirements of efficiency of the drilling work. A version of the reduction gear 4 is shown in Fig. 2. It comprises the stages of the planetary gear train including sun wheels 28 and 29, crown wheels 30 and 31, planet pinions 33, 33 with supports 34, and pinion carriers 35 and 36. The gear stages are interconnected by torque-transmitting couplings 37 which can be either splined or gear type. The driving shaft 38 of the transmission is connected with the input shaft 6 via the coupling member 39 and coupling 10 (Fig. 1) while the driven shaft of the reduction gear - pinion carrier 36 - is connected by the coupling 10 with the output shaft 8. The 1st friction stage of the reduction gear is made to function as a torque stabilizer, i.e,, a device eliminating the effect of torque fluctuations on the operation of the entire reduction gear. This is achieved by providing the friction stage with a spring 40 mounted on a shaft 38 and pressing the bevel sun wheels 28 against the tapered surfaces of the planet pinions 10~81~0 32 which, in turn, are pressed by the cylindrical surfaces against the crown wheel 30 connected with the reduction unit casing 1. The parameters of the spring 40 are such that the cornpression of the friction elements 28, 32, 30 ensures trans-rnission of a maxiltlum torque required for normal operation of the rock-breaking tool. When this torque starts fluctuating and l~s upsurges may ruin the reduction year elements, the friction elements of -the stage slip momentarily thus reducing the torque upsurge.
The 2nd toothed stage of the reduction gear incorporates an overload safeguard. It includes inserts 41 (Figs. 3,4) with the supports 34 of the planet pinions 33 which are installed in the slots E of the pinion carrier 36. The portion El of each slot E mating with the insert 41 has the form of a cylindrical surface whose axis is perpendicular to the longitudinal axis of the reduction gear (coinciding with the axis of the sun wheel 29) and intersects it. The surface F of the insert 41 mating with the cylindrical surface of the slot E is barrel-shaped (Fig. 4).
The surface G of the insert 41 (Fig. 3) facing the planet pinion 33 is flat. The planetpinions 33 with supports 34 and inserts 41 are located in the circular space between the sun wheel 29 ana the crown wheel 31 irregularly, in groups (Fig. 5) so that the distances between ~he axes of the adjacent planet pinions 33a and 33b within one group are shorter than the distances between the ~981~0 axes of the adjacent planet pinions 33b and 33c included in-to difFerent groups. Accordingly, the cross sectional aréas and thc moments of resistance of the pinion carrier elements 36a and 36b ~re different too.
All the above-mentioned d;stinguishing feal-ures of the toothed stage of the reduction gear are aimed at raising the load capacity of the wearest reduction gear elements such as supports 34, planet pinions 33 and pinion carrier 36. Thus, their load capacity rises sufficiently for transmitting the torque ensuring normal functioning of the drilling bit. When torque is transmitted via the reduction gear 4, its pinion carrier 36 is twisted relative to the longitudinal axis, the carrier elements 36a and 36b (Fig. 5) bend with respect to axes X - X and Y - Y which is accompanied by turning of the shafts of the planet pinions 33 (Fig. 3) through a certain angle.
The arrangement of the reduction gear 4 in accordance with the present invention raises the total moment of resistance of the carrier elements 36a and 36b in comparison with the reduction gear whose planet pinions are spaced regularly and uniformly in the circular spacè. The maximum effect is achieved when the planet pinions 33a and 33b are contiguous to each other (Fig. 5), i.e., when the axis-to-axis distances of the planet pinions 33a and 33b are minimum and meet all the requirements of assembling the planetary transmission. The stresses in said elements of the pinion carrier are reduced still more because a considerable radius R (Fig. 3) of the cylindrical surface practically excludes stress 1(~98~0 concentrations at the junctions between the longitudinal 36a and transverse 36c elements of the pinion carrier. The flat shape of ~he surfaces G makes it possible to reduce the total Lenyth of the s]ot E 2 which contributes to higher strength and stiffness of the pinion carrier. At the same time, installation of the planet pinion supports 34 in the inserts 41 permits increasing their diameters and longitudinal loading as compared with the versions in which the supports are located inside the planet pinions. The operating conditions of the supports 34 are made still better due to the barrel-like shape of the insert 41 which permits the supports 34 to be self-adjusted if the shaft of the planet pinions 33 is mis-aligned in two mutually perpendicular planes.
A version of the dividing space B (Fig. 6) incorporates an auxiliary seal in the form of an elastic diaphraym 42.
One side of the diaphragm 42 is reinforced by metal rings 43 which allows the diaphragm 42 to be press-fitted into the tubular element 13. At the other side the diaphragm fits around the bushing 12 secured on the shaft 6 with an interference of 5 - 7 mm for sealing said bushing but permitting the shaft 6 to rotate together with said bushing 12. This auxiliary seal divides the space B into two parts sl and B2. The space Bl accommodates a lubricating buffer fluid while the buffer fluid in the space B2 is gradually substituted by the drilling fluid.
As the fluid gradually escapes from ~9~ 0 the chamber A the lubricant is replenished from the space Bl.
An advantage of this version lies in a longer preservation of the buffer f]uid in the space s.
The version of the reduction unit of a drilling motor (J~'ig. 7) diffcrs from the basic version (Fig. 1) in that the dividing space B communicatcs hydraulically through channel L with the oil-filled chamber A which accommodates the reduction gear 4 and supports 11 : the chamber A, like the chamber B, is filled with a lubricious buffer fluid. In such an arrange-ment the pressure of the drilling fluid is conveyed from thespace B into the chamber A through channel L. When the fluid volume changes in the chamber A due to thermal variations and the fluid flows back and forth through channel L, pressure in said cham~er remains unchanged so that the seal 7 is practically free from the effect of pressure drop. Its functions consist only in preventing the settling solid particles from entering the chamber A when the fluid located in the upper part of the space B above the buffer fluid is not cleaned sufficiently well. Therefore, the design of the seal 7 is simpler than it 2C is in the basic version (Fig. 1). For example it has the form of an edge-type labyrinth gate. The reduction unit of a drilling motor according to this layout (Fig. 7~ is extremely simple, sufficiently reliable and durable.
The use of the above-described technical solutions has made it possible to work out a simple and dependable design ~981~0 of the EedUCtion l~it of a drilling motor ~hich allows-e~icient drilling of wells with variou~ type~ o~ drilling motors, practically at any depth attai~able today with the c:urrent hydraulic eguipment o~ the drilling rigs. ~e self-~suf~iciency o~ the unit and its oil protect:ion system permit its use in the form of a.set of several reduction unit~
ensuriDg a series of speed ratios capable o~ providing a wide range of performance characteristics required by diverse drilling conditions without changing the ~orking elements and motor supporting units. Said units can be ~urnished to the drilling rig in a set while the re~uired characteristic o~
the motor can be determined directly at the borehole by replac-ing or consecutivelg combining several rednction units.
, ~5- . .
, , , .
:~ -.
.
Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A reduction unit of a drilling motor installed between a working tool assembly and a drilling motor supporting assembly, comprising: a casing; adapter sleeves for connecting said casing with a housing of the working tool assembly and supporting assembly; a reduction gear with sun and crown wheels, pinion carriers and planet pinions with supports located in an annular space between the wheels; an overload safeguard preventing overloading of the reduction gear; a torque stabilizer eliminating any effect of torque fluctuations on operation of the reduction gear; input and output shafts of the reduction unit intended to transmit torque from the shaft of the working tool assembly to the reduction gear and from the reduction gear to a supporting assembly shaft; couplings installed on said shafts for transmitting torque and permitting relative axial displacements and axial misalignment of the connected shafts;
supports of said shafts installed on the ends of said shafts connected with the reduction gear and made in the form of an articulated unit taking axial loads and permitting angular displacements of the shafts; an oil-filled chamber accommodating said reduction gear, the overload safeguard of the reduction gear, the torque stabilizer thereof and the shaft supports, said chamber being secured on said casing so that the external surface on said chamber forms, together with the internal surface of the casing, an annular channel for drilling fluid; an oil protection system with seals installed on each of said shafts side by side with their supports at the side opposite to the reduction gear, the seals being provided with dividing spaces filled with buffer fluid which protects said seals from contact with the drilling fluid.
supports of said shafts installed on the ends of said shafts connected with the reduction gear and made in the form of an articulated unit taking axial loads and permitting angular displacements of the shafts; an oil-filled chamber accommodating said reduction gear, the overload safeguard of the reduction gear, the torque stabilizer thereof and the shaft supports, said chamber being secured on said casing so that the external surface on said chamber forms, together with the internal surface of the casing, an annular channel for drilling fluid; an oil protection system with seals installed on each of said shafts side by side with their supports at the side opposite to the reduction gear, the seals being provided with dividing spaces filled with buffer fluid which protects said seals from contact with the drilling fluid.
2. A reduction unit of a drilling motor according to claim 1, wherein the overload safeguard comprises inserts being installed in slots of the pinion carrier so that a part of each slot mating with the insert is made in the form of a cylindrical surface whose axis is perpendicular to, and intersects, the longitudinal axis of the reduction gear, the supports of the planet pinions being located in said inserts.
3. A reduction unit of a drilling motor according to claim 2, wherein the surface of the insert mating with the pinion carrier is barrel-shaped.
4. A reduction unit of a drilling motor according to claim 2, wherein the surface of the insert located at the side of the planet pinion is flat.
5. A reduction unit of a drilling motor according to claim 3, wherein the surface of the insert located at the side of the planet pinion is flat.
6. A reduction unit of a drilling motor according to claim 2, wherein the inserts with planet pinions are arranged in groups in which the distances between the axes of the adjacent planet pinions within one group are shorter than the distances between the axes of the adjacent planet pinions included into different groups.
7. A reduction unit of a drilling motor according to claim 6, wherein the distances between the axes of the adjacent planet pinions in the groups are as short as possible.
8. A reduction unit of a drilling motor according to claim 1, wherein the torque stabilizer eliminating any effect of torque fluctuations on the operation of the reduction gear comprises a friction stage forming part of the reduction gear, said friction stage including a spring designed to compress friction elements of said friction stage with a predetermined force.
9. A reduction unit of a drilling motor according to claim 1, wherein the articulated units are made in the form of spherical bearings.
10. A reduction unit of a drilling motor according to claim 1, wherein the input and output shafts are provided with additional supports connected to the casing by flexible elements.
11. A reduction unit of a drilling motor according to claim 10, wherein the supports connected to the casing by flexible elements are made in the form of radial rubber-metal sliding-contact bearings.
12. A reduction unit of a drilling motor according to claim 1, wherein the dividing spaces are limited by a seal, by a tubular element connected with the casing, and by a cover mounted on the shaft, said tubular element forming, together with the casing, a channel for the drilling fluid.
13. A reduction unit of a drilling motor according to claim 12, wherein the dividing space has an auxiliary seal in the form of an elastic diaphragm, the portion of said diaphragm connected to the tubular element being located at the side of the seal while its opposite portion fits around the shaft for sealing the latter.
14. A reduction unit of a drilling motor according to claim 1, wherein the density of the buffer fluid filling the dividing space is higher than the density of the drilling fluid.
15. A reduction unit of a drilling motor according to claim 14, wherein the buffer fluid is constituted by a lubricating fluid.
16. A reduction unit of a drilling motor according to claim 1, wherein the dividing spaces are in hydraulic commun-ication with the oil-filled chamber which is filled with the buffer fluid.
17. A reduction unit of a drilling motor according to claim 15, wherein the dividing spaces are in hydraulic communication with the oil-filled chamber which is also filled with the buffer fluid.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SU782566966A SU943385A1 (en) | 1978-01-09 | 1978-01-09 | Hole-bottom motor reduction gear |
| SU2566966 | 1978-01-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1098110A true CA1098110A (en) | 1981-03-24 |
Family
ID=20743342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA319,374A Expired CA1098110A (en) | 1978-01-09 | 1979-01-09 | Reduction unit of drilling motor |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS5851117B2 (en) |
| CA (1) | CA1098110A (en) |
| DE (1) | DE2900189C2 (en) |
| FR (1) | FR2414154A1 (en) |
| GB (1) | GB2014269B (en) |
| NL (3) | NL183472C (en) |
| SE (4) | SE444053B (en) |
| SU (1) | SU943385A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017158573A1 (en) * | 2016-03-17 | 2017-09-21 | Gearpower Group Ltd | A gear system |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2829502C2 (en) * | 1978-07-05 | 1982-03-18 | Zahnradfabrik Friedrichshafen Ag, 7990 Friedrichshafen | Gear for arrangement in an annular space between two coaxial tubes |
| US4548283A (en) * | 1981-01-12 | 1985-10-22 | Young David E | Rotating shaft seal and bearing lubricating apparatus |
| EP0129861B1 (en) * | 1983-06-27 | 1987-05-20 | Alsthom | Oscillating thrust-bearing device |
| FR2550301B1 (en) * | 1983-08-03 | 1987-12-18 | Alsthom Atlantique | METHOD OF PROTECTING A MECHANICAL SYSTEM WITH LIMITED MOVEMENTS AGAINST AN AGGRESSIVE ENVIRONMENT |
| FR2661963B1 (en) * | 1990-05-14 | 1995-03-03 | Yves Niel | SPEED REDUCER WITH EPICYCLOUIDAL TRAIN. |
| US5911284A (en) * | 1997-06-30 | 1999-06-15 | Pegasus Drilling Technologies L.L.C. | Downhole mud motor |
| DE102014215967A1 (en) * | 2014-08-12 | 2016-02-18 | Robert Bosch Gmbh | Hand tool gear unit |
| CN107489381B (en) * | 2017-09-28 | 2023-06-06 | 山西风雷钻具有限公司 | Overload-proof screw drilling tool |
| US11473653B2 (en) | 2018-06-06 | 2022-10-18 | Vectis Drive Inc. | Fixed ratio traction or friction drive |
| CN108868586B (en) * | 2018-08-21 | 2024-02-09 | 曾卫林 | Blade-free underground power drilling tool |
| CN115162943B (en) * | 2022-06-29 | 2023-04-18 | 重庆科技学院 | Coiled tubing drilling downhole planetary gear reducer |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2715344A (en) * | 1949-10-15 | 1955-08-16 | Arutunoff Armais | Planetary gear transmission for drilling apparatus |
| US2937008A (en) * | 1955-09-30 | 1960-05-17 | Whittle Frank | High-speed turbo-drill with reduction gearing |
| US3669199A (en) * | 1970-03-19 | 1972-06-13 | Youngstown Sheet And Tube Co | Drilling apparatus |
| SE7603757L (en) * | 1975-04-16 | 1976-10-17 | Empire Oil Tool Co | EXCHANGE SYSTEM |
-
1978
- 1978-01-09 SU SU782566966A patent/SU943385A1/en active
-
1979
- 1979-01-04 DE DE2900189A patent/DE2900189C2/en not_active Expired
- 1979-01-05 GB GB7900419A patent/GB2014269B/en not_active Expired
- 1979-01-08 FR FR7900367A patent/FR2414154A1/en active Granted
- 1979-01-09 NL NLAANVRAGE7900168,A patent/NL183472C/en not_active IP Right Cessation
- 1979-01-09 SE SE7900200A patent/SE444053B/en not_active IP Right Cessation
- 1979-01-09 JP JP54001723A patent/JPS5851117B2/en not_active Expired
- 1979-01-09 CA CA319,374A patent/CA1098110A/en not_active Expired
-
1985
- 1985-06-28 SE SE8503275A patent/SE8503275D0/en not_active Application Discontinuation
- 1985-07-01 SE SE8503274A patent/SE459875B/en not_active IP Right Cessation
- 1985-07-29 SE SE8503276A patent/SE8503276L/en not_active Application Discontinuation
-
1987
- 1987-02-17 NL NL8700399A patent/NL8700399A/en not_active Application Discontinuation
- 1987-02-17 NL NL8700400A patent/NL8700400A/en not_active Application Discontinuation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017158573A1 (en) * | 2016-03-17 | 2017-09-21 | Gearpower Group Ltd | A gear system |
Also Published As
| Publication number | Publication date |
|---|---|
| NL8700399A (en) | 1987-06-01 |
| SE8503275L (en) | 1985-06-28 |
| SE8503276D0 (en) | 1985-06-28 |
| JPS54116554A (en) | 1979-09-10 |
| SE8503276L (en) | 1985-06-28 |
| SE8503275D0 (en) | 1985-06-28 |
| FR2414154B1 (en) | 1983-10-28 |
| DE2900189C2 (en) | 1983-10-27 |
| NL183472B (en) | 1988-06-01 |
| GB2014269B (en) | 1982-08-18 |
| SE444053B (en) | 1986-03-17 |
| JPS5851117B2 (en) | 1983-11-14 |
| SE7900200L (en) | 1979-07-10 |
| SE459875B (en) | 1989-08-14 |
| GB2014269A (en) | 1979-08-22 |
| SE8503274D0 (en) | 1985-06-28 |
| FR2414154A1 (en) | 1979-08-03 |
| NL7900168A (en) | 1979-07-11 |
| DE2900189A1 (en) | 1979-07-19 |
| SU943385A1 (en) | 1982-07-15 |
| NL183472C (en) | 1988-11-01 |
| SE8503274L (en) | 1985-07-01 |
| NL8700400A (en) | 1987-06-01 |
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