US3774697A

US3774697A - Rotary drive assembly for handling tubular members

Info

Publication number: US3774697A
Application number: US00206325A
Authority: US
Inventors: C Brown
Original assignee: C Brown
Current assignee: Hughes Tool Co
Priority date: 1971-12-09
Filing date: 1971-12-09
Publication date: 1973-11-27
Anticipated expiration: 1990-11-27

Abstract

A reversible, electric motor drive assembly pivotably supported from the traveling block in a derrick is employed to rotate, raise, lower or otherwise handle tubular pipe used in the drilling and production of oil and gas wells. Mechanical cushioning means support the assembly from the traveling block and swivel type connections are employed to provide fluid communication between external supply and return points and fluid conductors carried in the rotatable output drive of the drive assembly. In a modified form, a reduction gear with variable gear ratios is employed to power a dual conduit system which provides a fluid passage for conveying drilling fluids to the drill bit and a separate passage for returning fluids and cuttings to the wellhead.

Description

United States Patent [1 1 Brown ROTARY DRIVE ASSEMBLY FOR HANDLING TUBULAR MEMBERS Filed:

Inventor: Cicero C. Brown, Houston, Tex.

Dec. 9, 1971 Appl. N0.: 206,325

Related US. Application Data Continuation-impart of Ser. No. 130,597, April 2, 1971.

US. Cl 173/20, 173/57, 173/164,

Int. Cl E2110 17/05 Field of Search l7 3 /2 Q 5 7 14 References Cited UNITED STATES PATENTS Hanson Winter et al Alexander et al. Arthur Homanick 175/85 X 3,774,697 Nov. 27, 1973 1,949,908 3/l934 Hawk l73/20 X Primary Examiner-Ernest R. Purser Att0meyCaIlos A. Torres et al.

[57] ABSTRACT A reversible, electric motor drive assembly pivotably supported from the traveling block in a derrick is employed to rotate, raise, lower or otherwise handle tubular pipe used in the drilling and production of oil and gas wells. Mechanical cushioning means support the assembly from the traveling block and swivel type connections are employed to provide fluid communication between external supply and return points and fluid conductors carried in the rotatable output drive of the drive assembly.

In a modified form, a reduction gear with variable gear ratios is employed to power a dual conduit system which provides a fluid passage for conveying drilling fluids to the drill bit and a separate passage for returning fluids and cuttings to the wellhead.

13 Claims, 6 Drawing Figures PAIENTED 1913 3774.697

SHEET u U 6 A 7' 7 DEA/E Y5 ROTARY DRIVE ASSEMBLY FOR HANDLING TUBULAR MEMBERS CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of U. S. Patent application, Ser. No. 130,597 entitled ELECTRIC POWER SWIVEL AND SYSTEM FOR USE IN RO- TARY WELL DRILLING, filed Apr. 2, 1971.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 'means for handling tubular fluid conducting members. In the specific application to be described, the present invention relates to vertically movable powered drive means for imparting rotary, vertical and pivotal motion to drill pipe and other tubular well members employed in the drilling and production of petroleum wells.

2. Brief Description of the Prior Art In the conventional method of drilling wells, large internal combustion engines or other power sources are employed to rotate a rotary table set in the floor of a drilling derrick. Rotary motion of the rotary table is conveyed to a square kelly which is free to slide vertically through the rotary table while it is rotated by the table. The lower'end of the kelly is threadedly engaged to the upper end of a string of drill pipe and the rotary motion is carried to a bit located at the lower end of the string.

As lengths of pipe are added to or removed from the drill string, it is necessary to employ auxiliary equipment such as wrenches, tongs, ropes and chains to threadedly engage and disengage the pipe members employed in the string. The technique, which is well known, is slow and extremely dangerous.

Other operations conventionally employed during the drilling of a well may require cocking the kelly over to connect into or release a short length of drill pipe. The cocking and threading or unthreading requires manual movement of the heavy equipment away from its normal vertical position which again necessitates the use of cumbersome, dangerous equipment.

In the parent of the present application, the power swivel therein described employs a central bore extending through the shaft of the electric motor for the purpose of communicating drilling fluids to the tubular drill pipe driven by the power assembly. This requires that a conventional, off-the-shelf electric motor be modified by formation of a concentric fluid conducting bore through the motor shaft. The modification may invalidate the manufacturers warranty for the motor and may also adversely affect the strength of the shaft.

The assembly described in the parent application also employs an hydraulic, shock loading or cushioning system to suspend the assembly from the traveling block. In some applications, a cushioning or support assembly having the high load capabilities of a hydraulic system is not required and a smaller, more direct mechanical cushioning system may be desirable.

SUMMARY OF THE INVENTION The assembly of the present invention provides vertical, rotary and angular movement in tubular well pipes as required in the drilling and completion of petroleum wells. These needs are provided without the use of cumbersome rotary tables and slow, dangerous auxiliary equipment. In the present invention, a reversible,

electric motor with variable reduction gearing is mounted as a vertically and pivotably movable assembly in a well derrick and is employed to handle the tubular members employed in the drilling and production of a well.

Fluid communication with the rotating tubular drive at the output end of the assembly is provided directly without the need for fluid communication through the drive shaft of the electric motor. By eliminating the need for the bore in the electric motor shaft, the shaft strengthis maintained and there is no invalidation of the equipment manufacturers warranties due to modification.

A mechanical spring shock absorber is employed to suspend and cushion the assembly from the traveling block. A simple, low cost mechanical spring suspension is employed so that the assembly may be used in relatively low stress applications without the need for a hydraulic cushioning system.

The assembly of the present invention is equipped with increased gearing output ranges to provide greater versatility. Gear reductions of 6 to 1 and 36 to l are employed in different forms of the invention. In one form of the invention, a gear shift provision is employed so that the assembly may operate in either a 6 to 1 reduction range, or by activation of the hydraulically driven gear shift means, in a 36 to 1 reduction range. By this means, the need for an expensive, variable speed electric motor with high performance characteristics is eliminated while maintaining the desired output rotation ranges.

These and other features and advantages of the present invention will be better understood from the following specification, the related drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial vertical elevation schematically illustrating the rotary drive assembly of the present invention in a well drilling derrick;

FIG. 2 is a vertical elevation in quarter-section illustrating the preferred form of the rotary drive assembly of the present invention;

FIG. 3 is a horizontal cross-section taken along the line 3-3 of FIG. 2;

FIGS. 4A and 4B are vertical elevations in quartersection illustrating respectively the upper and lower portions of a modified form of the rotary drive assembly of the present invention; and

FIG. 5 is a horizontal cross-section taken along the line 5-5 of FIG. 4A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the rotary drive assembly of the present invention is indicated generally at 10 suspended from a derrick D by a traveling block B. Two vertically extending tubular guides G (only one is visible) project upwardly from a derrick floor DF to provide guidance to the assembly 10 and to prevent counter-rotation of the assembly. The assembly 10 is connected to the guide members G by sleeves S which slide along the guide members to permit vertical movement of the assembly as the block B is moved through the derrick G. An hydraulic piston assembly P extends between the block B and a connector arm A rigidly connected to a main housing 11 in the assembly 10. Extension of the hydraulic cylinder P rotates the assembly 10 about dual pivotal mountings indicated generally at M (only one mounting is visible in FIG. 1) so that a tubular output drive shaft extending from the base of assembly is inclined with respect to the vertical. In FIG. 1, the output drive shaft 0 has been inclined into the dotted position to be attached to a length of pipe L which is driven up to the end of the shaft 0 by any suitable means (not shown). The end of output shaft 0 is equipped with threads to threadedly engage a pipe or may also be equipped with movable gripping means for frictionally grasping and securing the tubular members to be handled. One such form of gripping means is described in the aforementioned application, Ser. No. 130,597. Flexible electric and hydraulic lines are made up into a cable E which extends to the assembly 10 to provide control signals and power which regulate the various tilting, rotational and grasping movements of the assembly. A second flexible cable F connects directly into the output drive shaft 0 through a connector F to provide drilling fluids to a central flow passage into the output drive shaft 0.

Operation of the assembly 10 is controlled from a control panel C. Electric and/or hydraulic control lines CL extend from the control panel C and communicate with the cable E to convey control currents and power to a reversible electric motor (not visible) contained within the assembly 10. By manipulation of the controls on the panel C, the electric motor in the assembly 10 may be caused to rotate to the right or left or to start or stop. Other controls carried in the line CL are employed to regulate expansion and contraction of the hydraulic cylinder P to thereby determine the angle of inclination of the output drive 0, to control the vertical movement and position of the traveling block B, to control grasping and release of pipe gripping mechanisms carried by the drive 0, and to control the flow of fluids through the line F. In addition, the control panel C is equipped with visual indicators for showing the weight suspended from the assembly 10, the rate of rotation of the shaft 0, and the rate of penetration or rate of vertical movement of the assembly and other variables which must be monitored in the drilling operation.

When an additional length of pipe must be added during drilling operations, the assembly 10 is cocked over into the dotted line position to engage the upper end of the length of pipe L. Rotation of the output shaft 0 causes the shaft to threadedly engage the pipe section L and the block B is then rajsedwhile the output shaft means is moved into its vertical position. The lower, female end of the pipe section L (not illustrated) is positioned over the top of a drill string DS and rotated by the assembly 10 to threadedly engage the pipe L and the drill string. Subsequently, the entire drill string, including section L is supported from the assembly 10 which in turn is supported by the traveling block B. The electric motor in the assembly 10 is then activated to induce rotation of the output shaft 0, attached pipe L and drill string DS to impart a rotary motion to a drill bit (not illustrated) secured to the bottom of the drill string. Other conventional operations including removing or replacing the entire drill string and positioning or removing production tubing may be per formed by the assembly 10 by raising, lowering, rotating, or pivoting the pipe or tubing as required.

Details in the construction of the assembly 10 are illustrated in FIG. 2 of the drawings. The main housing ll of the assembly is a substantially annular, hollow body which encases the upper end of the rotatable output shaft 0 and the reduction gears connected between the motor shaft and the output shaft. The upper end of the housing 1 1 is closed over by a circular, centrally apertured plate 12. The housing 11 includes two radially extending

suspension ears

14 and 15 positioned 180 from each other. With specific reference to the suspension ear 14 which is similar in construction to the ear 15, an axially extending bore 17 formed through the ear 13 confines a metal coil spring 18 employed to cushion the assembly 10 in its suspension from the block B. A connecting rod 19 extends through the spring 18 and through a bore in the plate 12. The spring 18 is maintained within the bore 17 between a threaded nut 20 engaging the lower end of the rod 19 and an internal shoulder 170 formed at the upper end of the bore 17. The upper rod end includes a clevis connection 21 through which a pin 22 is inserted to secure an arm 23 employed to secure the assembly to the block B. A similar arm 24 connected with a pin 25 inserted through a clevis connection 26 cooperates with the arm 23 to provide dual supports at opposite sides of the assembly 10.

A reversible electric motor (not illustrated) encased within a motor housing 27 is employed to provide power in the form of rotary motion in a motor shaft 28. A top plate 27a is secured to the housing 27 by bolts 27b and bolts 270 secure the motor housing to the plate 12. The upper end of the shaft 28 is mounted between radially supporting ball bearings 29 and the lower shaft end is threadedly engaged to a tubular gear support body 30. The construction of the electric motor and its mounting within the housing 27 are conventional. A central spur gear 31 equipped with gear teeth 31a is mounted on and locked to the support body 30 for rotation therewith. Suitable locking means such as the key 31b fix the pinion gear 31 on the motor output shaft 28 to prevent the gear and mounting 30 from rotating with respect to the shaft 28. O-ring seals 12a and 12b prevent debris from entering the housing 11. The seal 12a is adapted to slide along a smooth outer surface on the gear 31. An annular bearing mount 32 encircles the gear 31 and supports an inner face member 33 on inclined roller bearings 34. An outer race 35 for the bearings 34 is mounted concentrically within the circular path 12. The roller bearings 34 are employed for preloading the rotatable drive assembly and provide both axial and radial friction reducing support.

With joint reference to FIGS. 2 and 3, three planetary gears indicated generally at 36, 37 and 38 are mounted for rotary motion about shafts secured to a circular mounting head formed at the upper end of a tubular output drive shaft 39. The lower end of shaft 39 forms the output drive shaft 0. The centers of the gears 36-38 are positioned on the same radius and are spaced from each other. The three gears 36-38, which are the same will be described with specific reference only to gear 36. The gear 36 includes a central shaft 40 which is mounted in a receiving recess 41 formed in the top surface of the mounting head on shaft 39. Socket head bolts 42 hold the shaft 40 in firm engagement with the shaft 39 and ball bearings 43 mount an annular gear ring 44 about the shaft 40. The ring 44 is equipped with external gear teeth 44a which mesh with the gear teeth 31aon the pinion gear 31 and also mesh with the gear teeth 45a formed internally of a large ring gear 45. The gear 45 is rigidly secured to the plate 12 by suitable socket head bolts 46.

Rotary and axial support for the large weight which is to be suspended from the output drive shaft 39 is provided by tapered roller bearings 47 supported between lower and

upper races

48 and 49, respectively. The lower race 48 is supported on an annular I-I-beam collar 50 which in turn is supported on an internal shoulder formed in the housing 11. A conventional strain gauge 51 is attached to the upstanding web connecting the upper and lower portions of the collar 50 and suitable electrical leads 51aextend to the control panel C to provide an input signal to a transducer which forms a visible indication of the weight being supported by the shaft 39.

At the lower end of the housing 11, shaft 39 is supported radially by roller bearings 52. An annular fitting 53 secured to the base of housing 11 by bolts 54 mounts a resilient seal 55 adapted to bear against and seal with a rotatable sleeve 56 secured by bolts 56a to a restricted portion 39a of the output drive shaft 39. The fluid connector indicated generally at F includes a tubular sleeve 57 which extends about the sleeve 56. The connector F which is secured to the base of housing 11 by the bolts 54 employs upper and lower

annular packing

58 and 59 to form a sliding, leakproof seal between the

sleeves

56 and 57. An input flow connector nipple 60 connects to the sleeve 57 and is equipped with a fluid conducting passage 60a which communicates with an annular passage 61 formed between the

sleeves

56 and 57. The passage 60a communicate with radial bores 62 extending through the sleeve 56 and into the tubular body of the drive shaft 39. Upper and lower O-

ring seals

63 and 64, respectively prevent fluid leakage between the sleeve 56 and shaft 39. The flow connector F is employed to convey drilling fluids from a stationary external supply point (not illustrated) to a rotatable, central flow passage 65 extending centrally through the tubular output drive shaft 39.

An annular control line connector ring 66 secured to the base of the tubular body 57 by suitable bolts 67 cooperates with annular O-rings 68, 69 and 70 to provide sliding seals with the shaft 39 which isolate two separate fluid conducting paths 72 and 73. The two flow paths 72 and 73 may be employed to convey hydraulic control fluid to automatic pipe gripping slips (not illustrated) or other automated assemblies connected to the end 0 of the output drive shaft.

Referring jointly to FIGS. 1, 2 and 3, the pivotable mounts M include radially extending pins 74 projecting through bores carried at the ends of guide connecting arms 75. The arms 75 extend to and connect with the guide sleeves S. Ball bearings 76 are mounted between the pins 74 and the receiving bores of the arms 75. The two arms 75 cooperate with the sleeves S to provide a structure which permits pivoting and vertical movement of the assembly while preventing rotation of the assembly caused by reaction to rotary motion of the output drive shaft 39. A pin 77 extends through a clevis 78 to pivotably secure the lower end of the hydraulic cylinder P to an eye brace 79 extending from the housing 1 l.

OPERATION OF THE ASSEMBLY When the output drive shaft end 0 is secured to a drill string, the weight of the string compresses the springs 18 between the shoulders 17a and the upper axial end of nut 20. The springs 18 function to cushion and absorb sudden changes in vertical loading acting through the drive shaft 39 which may occur for example when the drill string is released from the assembly 10 or when the assembly is pulled downwardly away from the block B as the end 0 is threaded onto the top of the drilling string.

By appropriately moving controls on the control panel C, electrical energy is supplied through the cable E to the electric motor in the housing 27. Depending upon the function being performed, the rotation of the motor may be in either a clockwise or counterclock wise direction. Rotation of the motor rotates the shaft 28 and the attached pinion gear 31. As the gear is rotated, the meshing engagement of the gear teeth on the three planetary gears 36-38 with the teeth 31a and with the surrounding teeth 45a on fixed gear 45 causes the output shaft 39 to rotate within the housing 11. Rotation of the shaft 39 is imparted to equipment or pipe strings attached to the output shaft end 0. Six complete rotations of the motor shaft 28 are required to produce a single rotation in the output shaft 39 for a six to one reduction.

During conventional drilling operations, drilling fluid is supplied through the drill string to the bit. Drilling fluid entering the connector F communicates with the central flow passage 65 in the rotating output shaft 39 to provide the desired fluid flow.

MODIFIED ASSEMBLY A modified drive assembly is depicted generally at in FIGS. 4A and 4B. The assembly 110 is similar to the previously described assembly 10 except that the modified assembly is equipped with a 36 to 1 reduction capability whereas the assembly 10 is limited to a six to one reduction. In addition, the assembly 110 is equipped with provision for converting gearing ratios between 6 to l and 36 to l and also includes dual flow passages for both conveying drilling fluid to the drill bit and returning the fluid and fluid carried cuttings to the well surface. Load distributing means are also included in the modified assembly 110 for assisting in equally distributing forces acting in the assembly to improve smoothness of operation and prolong the life of the various moving components.

The assembly 110 includes a main housing 111 covered at its upper end by a centrally apertured, circular plate 112. Dual suspension ears 114 and 115 are employed to suspend the assembly from the traveling block. With specific reference to the ear 114, an axially extending bore 117 is formed through the housing 111 to receive a shock absorbing coil spring 118. A connecting rod 119 projects upwardly through the bore 1 17 and connects to the suspension structure extending from the assembly 110 to the traveling block. A threaded nut 120 holds the spring 118 in place within the bore 117. An eye member 121 is threadedly engaged to the upper end of the rod 119 and connects with a pin 122 passing through a clevis fitting 123. A connecting rod 123a threadedly engaged to the clevis fitting 123 extends upwardly and meets with a second arm 124a connected to a clevis fitting 126 extending upwardly from the ear 115 at the opposite end of the assembly. The two

suspension structures

123a and 124a meet at a single point (not illustrated) from which the assembly is suspended from the traveling block.

An electric motor housing 127 is bolted to the plate 112 and an electric motor (not illustrated) in the housing 127 rotates a central motor shaft 128. The upper end of the shaft 128 is mounted for rotation in upper ball bearings 129 and the lower end of the shaft is threadedly engaged with a gear support 130 upon which an annular spur gear 131 is mounted and fixed. Inclined roller bearings 134 are used to align and preload the shaft 128. Three planetary gears such as gear 136 are mounted in the upper surface of a circular mounting head formed at the top of a shaft 139. It will be appreciated that the three gears similar to gears 136 are mounted and disposed in a manner similar to that of gears 36-38 illustrated in FIG. 3. The gears of assembly 110 differ from those in the assembly in that the former are equipped with load equalizing means to be hereinafter described. The gear 136 includes a gear shaft 140 encircled by ball bearings 143 which rotatably mount a circular gear 144. External gear geeth on the gear 144 mesh with gear teeth 145a formed along the internal surface of a large annular ring gear 145. The gear 145 is mounted in upper and lower ball bearings 145b and 145e, respectively, for rotation within the housing 11.

As will be seen, rotation of the electric motor shaft 128 acts through a variable gear reduction system to impart rotation to a lower tubular output drive shaft 139a. Tapered roller bearings 147 support and align the shaft 139a for rotation within the housing 111. The bearings 147 are supported in an annular H-beam collar 150 equipped with a strain gauge 151. Output leads 151a connected with the strain gauge 151 connect to the control panel (not illustrated) to provide a visual indication of the total weight suspended from the assembly 110. Roller bearings 152 align and radially support the shaft 139a for rotation within the lower por tion of the housing 111.

Referring to FIG. 4B, a fluid input assembly F is formed by a tubular connecting sleeve 157 which surrounds the lower portion of the output drive shaft 1390. Upper and

lower packing

158 and 159 respectively, is positioned between the tubular connector body 157 and the cylindrical outer surface of the drive shaft 139a to provide a leakproof seal between the stationary fluid input connector F and the rotating output drive shaft 139a. The assembly F is secured to a return connector R by suitable bolts 157a. The connector R includes a tubular sleeve portion 157 which encircles the drive shaft 1390. Upper and lower packing 158' and 159' respectively is positioned between the sleeve 157' and the shaft 139a to provide a sliding, leakproof connection between the stationary connector R and the rotating shaft 139a. Upper and lower ball bearing and seal assemblies indicated generally at 157a and 157b' respectively assist in supporting the shaft 1390 for rotation within the stationary structures F' and R Openings 160a extend through input flow connector nipples 160 which communicate with radial bores 162 formed through the wall of the drive shaft 139a to convey drilling fluid into an axially extending, annular flow passage 165. Drilling fluids entering the nipples 160 flow in the direction of the arrows shown in the flow paths 160a through the radial ports 162 and into the annular input flow passage 165 where they are conducted downwardly to a drill bit (not illustrated) suspended from the assembly 110. Drilling fluid and fluid borne cuttings are returned up to the wellhead through a return flow passage a provided by a tubular conduit 165a carried within the tubular shaft 1390. The conduit165a extends down through a drill string DS' threadedly engaged with the threads 1390 at the output end 0 of the assembly 110. The tubular conductor 165a is secured to the drive shaft 1390 by suitable bolts 13% for rotation with the shaft 139a. Packing 1390 between the inner conduit 165a and the shaft 139a provides a leakproof connection between the two members to isolate the input flow passage 165 from the return flow passage 165a. Fluid and returns flowing in the return passage 165a flow through radial openings 162a formed in the walls of the shaft 139a and enter an output passage162a' extending through return flanges 162b in connector R'.

Referring back to FIG. 4A, two pins such as the pin 174 extend through openings provided in connecting arms 175 which are secured to guide sleeves (not illustrated). Ball bearings 176 are disposed between the arms 175 and the pins 174 to permit pivoting of the assembly 110.

The gearing connection between the motor shaft 128 and the output drive shaft 139a is provided by the three planetary gears such as the gear 136, already described, acting in cooperation with an additional set of planetary gears indicated generally at 180, 181 and 182. With joint reference to FIGS. 5 and 4A, the gears -182 are similar to the three gears (such as the gear 136) mounted in the mounting plate at the upper end of the shaft 139. With specific reference to the gear 180, ear teeth 180a mesh with gear teeth 183a formed along the internal surface of a stationary ring gear 183. The gear 183 is secured to the housing 111 by bolts 184. The gear teeth 180a also mesh with gear teeth 139e formed along the lower portion of the shaft 139. The gears 180-182 are mounted in the shaft 1390 so that rotation of the shaft 139 acts through the gears 180-182 to impart a rotary motion to the shaft 139a. Suitable ball bearings 186 support the shaft 139 for rotary motion within the housing 111. Upper shaft supports 187 assist in mounting and aligning the central shafts of gears 180182.

A load distributing means 188 is connected by arms to the central shafts in each of the gears 180-182. The load distributing mechanism includes a circular plate member 1880 through which three slots 188b are provided. Axially extending pins 1880 connected to the ends of arms 188d extend downwardly through the slots 188a. The opposite ends of the arms 188d fit over hubs 188e formed on the lower ends of the shafts on which the gears 180-182 are mounted. The hubs 188e are eccentric with respect to the center of the central shafts and any unequal load distribution on any one of the three shafts is transmitted through the arms 188d to the plate member 188a and to the shafts in either of the other two gears to distribute the load equally about the assembly. A similar load distributing mechanism 188 is employed with the three gears driven by the spur gear 131.

Provision for shifting or altering the gear reduction ratio between a maximum of thirty-six to one to a lower six to one ratio is provided by a gear shift assembly indicated generally at 190. The assembly 190 is carried in a centering plate 190' and includes a fluid driven piston 191 which is raised or lowered in a bore 191a by fluid pressure applied through

hydraulic lines

192 and 193. The piston 191 connects to a locking .member 194 which is equipped with teeth 194a and 194b. The teeth 194a are adapted to engage gear teeth 195 formed along the outer edge of the circular mounting head at the upper end of the shaft 139 and the teeth 194b are adapted to engage gear teeth 196 carried on the ring gear 145 and teeth 183b extending inwardly from the inner wall of the fixed gear ring 183. The teeth 195,

196 and 183b extend along the entire circumference of the members from which they project. In its lower position, the member 194 locks with teeth 196 and 183b to prevent rotation of the gear 145. In its upper position, the member 194 locks with

teeth

195 and 196 and is free of the ring gear 183 so that gear 145 may be rotated. The member 194 is rotatably mounted on rollers 191a which ride on a radial lip 191b extending outwardly from a support ring 1910. A connecting rod 191d extends from the piston 191 to the ring 1910 to raise and lower the ring as the piston is raised and lowered.

, OPERATION OF THE MODIFIED ASSEMBLY The tilting and shock absorbing suspension of the assembly 1 10 is similar to that described for the assembly 10. Other functions are also similar except that the assembly 110 is capable of providing either a 36 to 1 gear reduction or a 6 to 1 reduction depending upon placement of the member 194 in the shifting assembly 190. In addition, the assembly 110 is designed to conduct drilling fluid to the drill bit and return fluid and cuttings through a return passage formed internally of the drill string. conventionally, returns are brought to the well surface through the annular space between the drill pipe and the surrounding well bore.

With the member 194 in its lower position, rotation of the drive shaft 128 acts through the three gears (such as gear 136) and the stationary ring gear 145 to induce rotation in the shaft 139. Rotation of the shaft 139 in turn, rotates the gears 180-182 against the stationary ring gear 183 causing the lower shaft 139a to rotate. The gear reduction between the shaft 128 and the shaft 139 is 6 to l and the reduction between the shaft 139 and the shaft 139a is also 6 to l for an overall reduction between the shaft 128 and the shaft 1390 of 36 to 1.

When six to one reduction between the shaft 128 and the output shaft 139a is desired, the fluid control line 193 is pressured up to push the piston 191 upwardly which in turn causes the member 194'to lock the teeth 195 on the shaft 139 with the teeth 196 on the gear 145. Rotation of shaft 128 causes the gear 145 to rotate in the housing 111. The member 194 rotates about the lip 191b to keep the shaft 139 and gear 145 locked together. By this means, the rotation of shaft 128 is imparted on a one-to-one basis to the shaft 139. Rotation of the shaft 139 is then reduced by the gears 180-182 and cooperating fixed ring gear 183 to provide a six to one reduction between the rate of rotation of the shaft 128 and the rate of rotation of the shaft 139a.

With reference to FIG. 4B, drilling mud or other well fluids are introduced into the drill string through the nipples 160 in the stationary connector assembly F. The input fluid flows through the openings 160a through the bores 162 and down the annular passage 165 to the drill bit. A negative pressure is maintained at the return connector R so that fluids and fluid borne cuttings at the bottom of the well bore are drawn into the central conductor 165a and elevated through the passage a. The fluid and returns in the passage 165a flow through the radial openings 162a and into the flow passages 162a to be carried to a remote location where the cuttings are separated from the fluid and the fluid is recirculated.

While the foregoing invention has been described with specific reference to the use of an electric motor as the drive means, it will be appreciated that other suitable drives may be employed. Thus, hydraulic motors, pneumatic motors, internal combustion engines or other powering devices may be employed to impart the desired rotary motion to the output drive shaft. In addition, while 6 to l and 36 to 1 gearing ratios have been shown, different reduction ratios may be employed without departing from the spirit of the present invention. In addition, although hydraulic pivot means have been described for pivoting or tilting the assembly, it is apparent that other means such as electrically powered drives, or other suitable drives may be employed to provide the desired tilting function.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. In a rotary drilling system including a derrick, a vertically movable traveling block and a source of drilling fluids, a rotary drive assembly comprising:

a. a reversible, electrical motor supported from said traveling block and movable vertically therewith, said motor including a rotatable drive shaft;

b. gearing means connecting said drive shaft with a rotatable output drive means for providing a rate of revolution of said rotatable output drive means different than that of said rotatable drive shaft;

c. fluid connecting means between said drilling fluid source and said output drive means for conveying drilling fluids directly from said source to a fluid conductor carried by said rotatable output drive means;

d. telescoping tubular drive members included in said output drive means for forming separate, rotatable, fluid conducting passages; and

e. connecting means between said rotatable passages and non-rotating, external connection points.

2. In a rotary drilling system as defined in claim 1, gear shift means for altering the rate of rotation of said output drive means for a substantially constant drive shaft rotation rate.

3. In a rotary drilling system as defined in claim 1, said gearing means including automatic load distributing means.

4. In a rotary drilling system as defined in claim 1, cushioning means connecting said assembly with said traveling block for cushioning sudden changes in vertical forces resulting between said assembly and said traveling block.

5. In a rotary drilling system as defined in claim 4, said cushioning means including steel spring means.

6. In a rotary drilling system as defined in claim 1, pivot means for pivoting said output drive means with respect to the vertical for aligning non-vertically disposed members with said output drive means for connection thereto.

7. In a rotary drilling system as defined in claim 6, backup means for preventing rotation of said traveling block as said output drive means is rotated.

8. In a rotary drilling system as defined in claim 7, said gearing means including automatic load distributing means.

9. In a rotary drilling system as defined in claim 7, control panel means for controlling movement of said rotary drive assembly.

10. In a rotary drilling system as defined in claim 9, said control panel means including:

a. control means for regulating the raising or lowering of said assembly;

b. control means for regulating the onset and termination of rotation of said output drive means; and

0. control means for regulating the angular disposition of said output drive means.

11. In a rotary drilling system as defined in claim 10, said control panel means including load indicator means for forming a visual representation of the load on said assembly.

12. In a rotary drilling system as defined in claim 1, said gearing means including:

a. first gear means connected with said drive shaft means for rotation therewith;

b. second gear means for meshing engagement with said first gear means and movable by rotation of said first gear means; and

c. drive linkage means operatively connected between said telescoping drive member and said second gear means for imparting rotary motion from said second gear means to said drive member, said second gear means including a plurality of planatary gear means rotatable about gear axes fixed rel ative to said drive linkage means and said planatary gear means operatively meshing with a surrounding third gear means whereby rotation of said first gear means acts through said planatary gear means against said surrounding third gear means to rotate said drive linkage means.

13. In a rotary drilling system as defined in claim 12,

said gearing means further including:

a. third gear means operable by gear shift means for connection with said drive shaft means for rotation therewith;

b. fourth gear means for meshing engagement with said third gear means and movable by rotation of said third gear means; and

c. second drive linkage means selectively connected between said drive members and said fourth gear means by said gear shift means for imparting rotary motion from said fourth gear means to said drive member.

Claims

1. In a rotary drilling system including a derrick, a vertically movable traveling block and a source of drilling fluids, a rotary drive assembly comprising: a. a reversible, electrical motor supported from said traveling block and movable vertically therewith, said motor including a rotatable drive shaft; b. gearing means connecting said drive shaft with a rotatable output drive means for providing a rate of revolution of said rotatable output drive means different than that of said rotatable drive shaft; c. fluid connecting means between said drilling fluid source and said output drive means for conveying drilling fluids directly from said source to a fluid conductor carried by said rotatable output drive means; d. telescoping tubular drive members included in said output drive means for forming separate, rotatable, fluid conducting passages; and e. connecting means between said rotatable passages and nonrotating, external connection points.

10. In a rotary drilling system as defined in claim 9, said control panel means including: a. control means for regulating the raising or lowering of said assembly; b. control means for regulating the onset and termination of rotation of said output drive means; and c. control means for regulating the angular disposition of said output drive means.

12. In a rotary drilling system as defined in claim 1, said gearing means including: a. first gear means connected with said drive shaft means for rotation therewith; b. second gear means for meshing engagement with said first gear means and movable by rotation of said first gear means; and c. drive linkage means operatively connected between said telescoping drive member and said second gear means for imparting rotary motion from said second gear means to said drive member, said second gear means including a plurality of planatary gear means rotatable about gear axes fixed relative to said drive linkage means and said planatary gear means operatively meshing with a surrounding third gear means whereby rotation of said first gear means acts through said planatary gear means against said surrounding third gear means to rotate said drive linkage means.

13. In a rotary drilling system as defined in claim 12, said gearing means further including: a. third gear means operable by gear shift means for connection with said drive shaft means for rotation therewith; b. fourth gear means for meshing engagement with said third gear means and movable by rotation of said third gear means; and c. second drive linkage means selectively connected between said drive members and said fourth gear means by said gear shift means for imparting rotary motion from said fourth gear means to said drive member.